• Journal of the Korean Geotechnical Society
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• v.26 no.2
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• pp.5-14
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• 2010

In this study, cyclic triaxial tests were performed under anisotropically consolidated condition by using irregular earthquake loading to consider in-situ condition and seismic wave. Jumunjin sand with a relative density 50 percent was used in the tests. The consolidation pressure ratio (K) was changed from 0.5 to 1.0. The Ofunato and Hachinohe wave were applied as irregular earthquake loadings and liquefaction resistance strengths of each specimen were estimated from the excess pore water pressure (EPWP) ratio. As a results of the cyclic triaxial tests, EPWP ratio increased with increased K value. It shows that isotropically consolidated sand is more susceptible to liquefaction than anisotropically consolidated sand under equal confining pressure and dynamic loadings. From the test results, the relationship between K and EPWP ratio normalized by effective confining pressure and deviator stress was proposed. And a new factor which corrects the liquefaction resistance strength for the in-situ stress condition is proposed.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.35-43
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• 2013

As texture images have become prevalent throughout a variety of industrial applications, copyright protection of these images has become important issues. For this reason, this paper proposes a color-texture image watermarking algorithm utilizing texture properties inherent in the image. The proposed algorithm selects suitable blocks to embed a watermark using the energy and homogeneity properties of the grey level co-occurrence matrices as inputs for the fuzzy c-means clustering algorithm. To embed the watermark, we first perform a discrete wavelet transform (DWT) on the selected blocks and choose one of DWT subbands. Then, we embed the watermark into discrete cosine transformed blocks with a gain factor. In this study, we also explore the effects of the DWT subbands and gain factors with respect to the imperceptibility and robustness against various watermarking attacks. Experimental results show that the proposed algorithm achieves higher peak signal-to-noise ratio values (47.66 dB to 48.04 dB) and lower M-SVD values (8.84 to 15.6) when we embedded a watermark into the HH band with a gain factor of 42, which means the proposed algorithm is good enough in terms of imperceptibility. In addition, the proposed algorithm guarantees robustness against various image processing attacks, such as noise addition, filtering, cropping, and JPEG compression yielding higher normalized correlation values (0.7193 to 1).

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.197-205
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• 2015

Offshore structures for the gas production are exposed to the risk of gas leaks, and gas explosions can result in fatal damages to the primary structures as well as secondary structures. To minimize the damage from the critical accidents, the study of the dynamic response of structural members subjected to blast loads must be conducted. Furthermore, structural dynamic analysis has to be performed considering relationships between the natural frequency of structural members and time duration of the explosion loading because the explosion pressure tends to increase and dissipate within an extremely short time. In this paper, the numerical model based on time history data were proposed considering the negative phase pressure in which considerable negative phase pressures were observed in CFD analyses of gas explosions. The undamped single degree of freedom(SDOF) model was used to characterize the dynamic response under the blast loading. A blast wall of FPSO topside was considered as an essential structure in which the wall prevents explosion pressures from the process area to utility and working areas. From linear/nonlinear transient analyses using LS-DYNA, it was observed that dynamic responses of structures were influenced by significantly the negative time duration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1457-1462
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• 2004

This study was conducted to investigate the effects of Aralia elata, Acanthopanacis cortex and Ulmus davidiana water extracts on plasma glucose and biomarkers in the streptozotocin (STZ)-induced diabetic rats. Male Wistar rats were divided into normal and diabetic groups. The diabetic groups subdivided into the control group (DM), Aralia elata (DM-AE), Acanthopanacis cortex (DM-AC) and Ulmus davidiana (DM-UD). The extracts were supplemented in diet base on 11.42 g of raw materials/㎏ diet for 7 weeks. The diabetes was induced by injecting STZ (55 ㎎/㎏ B.W., i.p.) once 2 weeks before sacrifying. Plasma glucose level was significantly higher in the DM group than in the normal group, whereas insulin and C-peptide concentrations were significantly lowered in the DM groups compared to the normal group. These parameters were normalized in the DM-AE, DM-AC and DM-UD supplemented groups. Plasma albumin content was significantly lowered in the DM group compared to the normal group, yet it was significantly higher in the DM-AE group than in the DM group. Bilirubin and creatinine contents were elevated in the DM group, while the supplementation of Aralia elata, Acanthopanacis cortex and Ulmus davidiana water extracts ameliorate the change of these contents in STZ-induced diabetic rats. Plasma AST, ALT, ALP and LDH activities were significantly higher in the DM group than in the normal groups. The supplementation of Araliaceae family water extracts significantly lowered these parameters compared to the DM group. Accordingly, these results indicate that Aralia elata, Acanthopanacis cortex and Ulmus davidiana water extracts would seem to improve the glucose and biomarker in STZ-induced diabetic rats.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.49-53
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• 2016

Purpose Recently, Cadmium-zinc-telluride (CZT) semiconductor myocardial SPECT (Single Photon Emission Computed Tomography) has been used myocardial scintigraphy. In this study, the performance of Semiconductor SPECT and conventional SPECT systems was compared by a comprehensive analysis of phantom SPECT images. Materials and Methods Methods: We evaluated the DSPECT CZT SEPCT (Spectrum-dynamic) and INFINA conventional (GE). Physical performance was compared on reconstructed SPECT images from a phantom. Results For count sensitivity on cardiac phantom images ($counts{\cdot}sec^{-1}{\cdot}MBq^{-1}$), DSPECT had a sensitivity of conventional SPECT. This classification was similar to that of myocardial counts normalized to injected activities from phantom images (respective mean values, $counts{\cdot}sec^{-1}{\cdot}MBq^{-1}$: 195.83 and 52.83). For central spatial resolution: DSPECT, 9.47mm; conventional SPECT, 16.90mm. For contrast-to-noise ratio on the phantom: DSPECT, 4.2; conventional SPECT, 3.6. Conclusion The performance of CZT cameras is dramatically higher than that of conventional SPECT. However, CZT cameras differ in that spatial resolution and contrast-to-noise ratio are better with conventional SPECT, whereas count sensitivity is markedly higher with the DSPECT.

• The Journal of Internal Korean Medicine
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• v.30 no.3
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• pp.510-524
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• 2009

Objective : This study was designed to find the correlation between Sasang Constitution and heart rate variability(HRV). Method : There were 665 subjects (280 men and 385 women), between 39 and 72 years old. in a rural community. Sasang Constitution was diagnosed by a Sasang constitutional specialist using PSSC (Phonetic System for Sasang Constitution), face and tongue photo and checkup-list. A structured-questionnaire was used to assess the general characteristics. HRV was recorded using SA-2000 (medi-core). HRV was assessed by time domain and by frequency domain analysis. Metabolic syndrome was defined on the basis of clustering of risk factors, when three or more of the following cardiovascular risk factors were included : blood pressure, fasting blood sugar, triglyceride HDL-cholesterol, and abdominal obesity (waist). Because of the skewness of the data, logarithmic transformation was performed on the absolute units of the spectral components of HRV, and the resulting logarithmic values and normalized units were compared between the groups by a logistic regression. The 95% confidence interval (CI) of the odds ratio was used and calculated from the data laid out for a cross sectional study. Results : 1. Odds ratios of Taeeumin and Soeumin in female adults below 60 years old were significantly lower than that of Soyangin in LF norm and LF/HF ratio. Odds ratios of Taeeumin and Soeumin in female adults below 60 years old were significantly higher than that of Soyangin in HF norm. 2. There was no significant correlation between HRV and Sasang Constitution in female adults from 60 years old and over. 3. There was no significant correlation between HRV and Sasang Constitution in male adults. Conclusion : There is a statistically significant correlation between the HRV and Sasang Constitution. There is a tendency of increase in the sympathetic activity in Soyangin. There is a tendency of decrease in the parasympathetic activity in Taeeumin and Soeumin.

• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.493-503
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• 2014

A hierarchical classification scheme, which can reduce the spectral ambiguity and also reflect crop cultivation patterns from past land-cover maps, is presented for the purpose of the early production of crop classification maps in large-scale crop areas. Specifically, the effects of mixed pixels are minimized not only by applying a hierarchical classification approach based on different spectral characteristics from crop growth cycles, but also by considering temporal contextual information derived from past crop cultivation patterns. The applicability of the presented classification scheme was evaluated by a case study of Iowa State in USA with time-series MODIS 250 m Normalized Difference Vegetation Index(NDVI) data sets and past Cropland Data Layers(CDLs). Corn and soybean, which are major crop types in the study area and also display spectral similarity, could be properly classified by applying different classification stages and accounting for past crop cultivation patterns. The classification result by the presented scheme showed increases of minimum 7.68%p and maximum 20.96%p in overall accuracy, compared with one based on purely spectral information. In addition, the combination of temporal contextual information during classification was less affected by the number of NDVI data sets and the best overall accuracy of 86.63% was achieved. Thus, it is expected that this classification scheme can be effectively used for the early production of large-area crop classification maps in major feed-grain importing countries.

• Korean Journal of Remote Sensing
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• v.36 no.2_1
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• pp.199-215
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• 2020

A seagrass that is marine vascular plants plays an important role in the marine ecosystem, so periodic monitoring ofseagrass habitatsis being performed. Recently, the use of dronesthat can easily acquire very high-resolution imagery is increasing to efficiently monitor seagrass habitats. And deep learning based on a convolutional neural network has shown excellent performance in semantic segmentation. So, studies applied to deep learning models have been actively conducted in remote sensing. However, the segmentation accuracy was different due to the hyperparameter, various deep learning models and imagery. And the normalization of the image and the tile and batch size are also not standardized. So,seagrass habitats were segmented from drone-borne imagery using a deep learning that shows excellent performance in this study. And it compared and analyzed the results focused on normalization and tile size. For comparison of the results according to the normalization, tile and batch size, a grayscale image and grayscale imagery converted to Z-score and Min-Max normalization methods were used. And the tile size isincreased at a specific interval while the batch size is allowed the memory size to be used as much as possible. As a result, IoU was 0.26 ~ 0.4 higher than that of Z-score normalized imagery than other imagery. Also, it wasfound that the difference to 0.09 depending on the tile and batch size. The results were different according to the normalization, tile and batch. Therefore, this experiment found that these factors should have a suitable decision process.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.113-119
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• 2000

The Pansori is a Korean traditional vocal music that has a unique story and melody which converts deep emotion into art. It has both verbal and emotional components. which can be coordinated by large-scale neural network. The purpose of this study is to illustrate the cortical network activated by a Korean traditional opera, Pansori, with different emotional valence using functional MRI (fMRI).Nine right-handed volunteers participated. Their mean age was 25.3 and the mean modified Edinburgh score was +90.1. Activation tasks were designed for the subjects to passively listen to the two parts of Pansories with sad or hilarious emotional valence. White noise was introduced during the control periods. Imaging was conducted on a 1.5T Siemens Vision Vision scanner. Single-shot echoplanar fMRI scans (TR/TE 3840/40 ms, flip angle 90, FOV 220, 64 x 64 matrix, 6mm thickness) were acquired in 20 contiguous slices. Imaging data were motion-corrected, coregistered, normalized, and smoothed using SPM-96 software.Bilateral posterior temporal regions were activated in both of Pansori tasks, but different asymmetry between the tasks was found. The Pansori with sad emotion showed more activation in the light superior temporal regions as well as the right inferior frontal and the orbitofrontal areas than in the right superior temporal regions as well as the right inferior frontal and the orbitofrontal areas than in the left side. In the Pansori with hilarious emotion, there was a remarkable activation in the left hemisphere especially at the posterior temporal and the temporooccipital regions as well as in the left inferior and the prefrontal areas. After subtraction between two tasks, the sad Pansori showed more activation in the right temporoparietal and the orbitofrontal areas, in contrast, the one with hilarious emotion showed more activation in the left temporal and the prefrontal areas. These results suggested that different hemispheric asymmetry and cortical areas are subserved for the processing of different emotional valences carried by the Pansories.

• Journal of Embryo Transfer
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• v.29 no.2
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• pp.101-109
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• 2014

Matrix Metalloproteinases (MMP)-2 and -9 are participated in embryo development, implantation, remodeling of epithelial cell and ovulation. The objective of this study is to evaluate an impact of MMP2 and MMP9 on embryonic developmental competence as well as gene expression profiles of in vitro-produced bovine embryos. After in vitro fertilization, embryos of all groups were transferred into IVC-2 medium treated with MMP2 and MMP9 to check the optimum concentration on the basis of embryo development competence and cell numbers. The optimum concentrations for MMP2 and 9 were 1,200 ng/ml and 300 ng/ml. The blastocyst development competence was not different among 1,200 ng/ml of MMP2 vs. 300 ng/ml of MMP9 vs. combined MMP2 + 9 vs. control groups ($41.46{\pm}10.66$ vs. $37.73{\pm}8.92$ vs. $45.11{\pm}11.41%$ vs. $41.59{\pm}11.88$, respectively). Furthermore, the developmental competences to hatching and hatched blastocysts were not also different among the same groups ($79.84{\pm}12.63$ vs. $83.3{\pm}17.46$ vs. $78.55{\pm}14.48%$ vs. $72.02{\pm}14.09$). In addition, total cell number was significantly (p<0.05) greater in blastocyst treated with MMP9 300 ng/ml among all treatment groups. On the other hand, there was no significant difference of ICM vs. TE ratio in all groups. The expression of five out of six genes (i.e., MMP2, MMP9, IFNt, SSLP1 and HNRNPA2B1) was different among the groups. The expression of IFNt and HNRNPA2B1 genes was significantly greater in MMP9 (p<0.05), but there was no difference of MMP9 expression between MMP2 and MMP9 group (p>0.05). The normalized expression of MMP2 and SSLP1 was greater in MMP2 than other groups (p<0.05). In conclusion, MMPs treatment during IVC-2 medium was remarkably effected on blastocyst developmental competence and gene expression profiles that are related to embryo quality and implantation.