• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.49-58
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• 2005

In this paper, we proposed a blind watermarking algerian to use characteristics of a scalar quantizer which is the recommended in the JPEG2000 and JPEG. The proposed algorithm shifts a quantization index according to the value of each watermark bit to prevent losing the watermark information during the compression by quantization. Therefore, the watermark is embedded during the process of quantization, not an additional process for watermarking, and is adaptively applied as a assigned quantizer according application areas. Before embedding process, a LFSR(Linear feedback shift register) rearranged the watermark for the security of the watermark itself and in the embedding process, a LFSR is used to hide the watermarking positions. Therefore the embedded watermark can he extracted by only the owner who knows the initial value of LFSR without the original image. The visual recognizable pattern such as a binary image was used as the watermark. The experimental results showed that the proposed algerian satisfies the robustness and imperceptibility corresponding to the major requirement of watermarking. The results showed the largest error rate to be $5.7\%$ for attack. The experimental result which compares the proposed algorithm with the Mohamed algorithm showed that the proposed algorithm was better than it, exactly $4\~5$ times for the attacks of JPEG and JPEG2000.

• Geomechanics and Engineering
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• v.14 no.3
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• pp.247-255
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• 2018

Soil stabilization can make the soils becoming more stable by using an admixture to the soil. Lime stabilization enhances the engineering properties of soil, which includes reducing soil plasticity, increasing optimum moisture content, decreasing maximum dry density and improving soil compaction. Silica fume is utilized as a pozzolanic material in the application of soil stabilization. Silica fume was once considered non-environmental friendly. In this paper, the materials required are kaolin grade S300, lime and silica fume. The focus of the study is on the determination of the physical properties of the soils tested and the consolidation of kaolin mixed with 6% silica fume and different percentages (3%, 5%, 7% and 9%) of lime. Consolidation test is carried out on the kaolin and the mixtures of soil-lime-silica fume to investigate the effect of lime stabilization with silica fume additives on the consolidation of the mixtures. Based on the results obtained, all soil samples are indicated as soils with medium plasticity. For mixtures with 0% to 9% of lime with 6% SF, the decrease in the maximum dry density is about 15.9% and the increase in the optimum moisture content is about 23.5%. Decreases in the coefficient of permeability of the mixtures occur if compared to the coefficient of permeability of kaolin soft clay itself reduce the compression index (Cc) more than L-SF soil mix due to pozzolanic reaction between lime and silica fume and the optimum percent of lime-silica fume was found to be (5%+6%) mix. The average coefficient of volume compressibility decreases with increasing the stabilizer content due to pozzolanic reaction happening within the soil which results in changes in the soil matrix. Lime content +6% silica fume mix can reduce the coefficient of consolidation from at 3%L+6%SF, thereafter there is an increase from 9%L+6%SF mix. The optimal percentage of lime silica fume combination is attained at 5.0% lime and 6.0% silica fume in order to improve the shear strength of kaolin soft clay. Microstructural development took place in the stabilized soil due to increase in lime content of tertiary clay stabilized with 7% lime and 4% silica fume together.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.53-58
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• 2015

Engineers should take great care of characterizing the engineering properties of mudrock, because the uncemented mudrock can be considered as a hard rock in appearance. Therefore, the mudrock samples obtained from the cut slope in Gyeongki-do were tested to evaluate the strength characteristics of uncemented mudrock in this study. The performed tests are index properties, slake durability, and swelling tests for the classification of the mudrock for engineering practice. To evaluate the effect of water on the engineering properties of the uncemented mudrock, resonant column, triaxial compression and direct shear tests with various water contents were performed. With the increasing water contents, stiffness at very small to small strain region and the cohesion value of the strength parameters decrease. Based on the test results, engineers should take great care of evaluating the engineering properties of uncemented mudrock.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.105-114
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• 2004

Consolidation characteristics have been investigated by using Rowe cell consolidation tester for dredged soil, which is more than two times as much as the liquid limit. To examine the effects of variation of water content on consolidation characteristic, tests were carried out varying the initial water content from $100\%\;to\;150\%.$ The results were compared with the consolidation characteristics of remolded clay. The test results showed that the hither the initial water content of dredged clay was, the more noticeable the non-linear behavior of e-log P curves occurred. The variation of the gradient was apparent to load stage 40kPa and became less apparent after load stage 80kPa on the e-log P curves. Ratio of compression index stayed within the range suggested by Mesri and variation of initial water content has hardly influenced the coefficient of consolidation. On the contrary, it was found that the magnitude of consolidation load affects the vertical coefficient of consolidation. The variation of stratum thickness during consolidation processing needs to be taken into consideration since hydraulic fill would go through a much larger scale strain than land soil when it is subject to a load. In this study, the consolidation period considering the variation of stratum thickness was analyzed and the results were compared with those of existing consolidation studies which did not consider the variation of stratum thickness. According to the results of the study, the consolidation period of the ground with a larger strain was calculated more close to observed value in case of Mikasa theory which takes the variation of stratum thickness into consideration.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.110-117
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• 1983

This study was conducted to investigate the influence of load increment ratio on the secondary consolidation for the marine clay at Asan bay by the hyperbola method. The results were summarized as follow: 1. Calculated secondary consolidation by the hyperbola method was slightly less than the value of Casagrande's log t method, but the difference was very little, and the secondary consolidation could be easily calculated by the hyperbola method even if load increment ratio was small. 2. The secondary consolidation ratio was increased with the decrement of load increment ratio, and the creep phenomenon of the settlement curve occurred under the condition of small load increment ratio seemed to be caused by the secondary consolidation. 3. The secondary consolidation ratio occurred during the primary consolidation was irregular in the overconsolidated range, but it was increased with the decrement of load increment ratio in the normally consolidated range. 4. The coefficient of secondary consolidation was increased with the increment of the consolidation load, made a point of the inflection near preconsolidation. And the coefficient of secondary consolidation was decreased from consolidation load $2kg/cm^2$, showed independent of load increment ratio. 5. The coefficient of secondary consolidation was showed in proportion to compression index.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.227-236
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• 2003

The evaluation of the reliable strength and deformation characteristics of weathered granite masses is very important for the design of geotechnical structure under working stress conditions. Various types of laboratory test such as triaxial compression test can be performed to determine the strength parameters. However, it is very difficult to obtain the representative undisturbed samples on the site and also the rock specimen cannot represent rock mass including discontinuities, fracture zone, etc. This study aims to investigate the strength and deformation characteristics of granite masses corresponding to its weathering and develop a practical strength parameter evaluation method using the results of PMT. To predict weathering intensity and strength parameters of the weathered granite masess in the field, various laboratory tests and in-situ tests including field triaxial test and PMT are carried out. Based on the results of weathering index tests, the classification method is proposed to identify the weathering degree in three groups for the weathered granite masses. Using the analytical method based on the Mohr-Coulomb failure criteria and the cavity expansion theory, the strength parameters of rock masses were evaluated from the results of PMT. It shows that weathering intensity increases with decreasing the strength parameters exponentially. The strength parameters evaluated with the results of PM almost coincide with the results of field triaxial test.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.4
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• pp.684-695
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• 1995

The purpose of this study was to investigate the influence of the mechanical properties on drapability in the peach skin-like finished fabrics. For this study, the samples used were 50 kinds of peach skin-like finished fabrics. The mechanical properties such as tensile, shearing, bending, compressional, surface characteristic values, thickness and weight were measured with a KES-F system and drupe coefficient by drape tester. The relationship between the characteristic values and drape coefficicients of the peach skin-like finished fabrics results were obtained. 1. Peach skin-like finished fabric had $\pm$2o range of shearing, bending, compression, surface. properties, thickness and weight as compared with Japanese women's thin fabrics. The characteristic mixing values were better with the values of WC/T, W/T, etc. as compared with that of japanese women's thin fabrics. Accordingly, the peach skin-like finished fabrics had a little volume, excellent hanging and drapability as compared with japanese women's thin fabrics. 2. The drape coefficient of peach skin-like finished fabric had a high level of correlation between 2HB, G, WC, MIU, WT, MMD, 2HG, RT, W, B etc. of the mechanical properties. The blocked properties that contributed to the drape coefficient of peach skin-like finished fabrics were in the order of the bending> tensile> thickness> weight properties. This drape coefficients(DC) were found by measuring the mechanical properties according to the obtained regress on equate on. DC=99.0179+17.9023 log G -17.0543 log 2HG5+17.2104 log 2HG+35.7685 log 2HB+ 4.6082 log B-30.5906 log T+4.2308 log W 3. The contribution to the drape coefficient of the characteristic mixing values of peach skin-like finished fabric was in the order of > 2HB/W> 2HB/B> B/W The drape coefficients were found by measuring the characteristic mixing values according to the obtained regression equation. 4. The drape coefficients of peach skin-like finished fabrics were influenced by the differences between the bending of warp direction, bending of weft direction, shearing etc which in turn determine the level of hanging. The regression equation was as follows; 5. The drape coefficients of peach skin.like finished fabrics had a highly positive correlation with the node index. It has an negative correlation with number of nodes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.899-904
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• 2004

The objectives of the experiment were to examine the effects of extrusion process variables on the yield of extruded ginseng extract and to determine the effect of ratio of extruded ginseng extract and microcrystalline cellulose on characteristics of spheronized granules by cold extrusion-spheronization process. Extrusion process variables observed were feed moisture (15, 22, 29%), die temperature (90 110 13$0^{\circ}C$) and screw speed (150 200, 250 rpm). The results showed that moisture content of dried ginseng significantly affected extraction yield (P<0.05). The less moisture content of the feed resulted in the higher yield of the extract. Moisture content of 15%, screw speed of 250 rpm and die temperature of 13$0^{\circ}C$ gave the highest yield of ginseng extract. Mean extraction yield of extruded ginseng using hot water extraction was greatly improved by extrusion process The extract yield of extruded ginseng was 43.5% which was higher than that of red ginseng (38.3%) and white ginseng (29.0%) produced by traditional process. It was possible to make from the mixture of microcrystalline cellulose (200 g) mixed with different concentration of 200 mL solution (0, 5, 20, 30 40 50 60% of ginseng extract with 59.2% dry solid) by using cold extrusion spheronization. When the concentration of ginseng extract Increased, the granulation yield was improved but friability and compression index were reduced. Ginseng extract such as saponin was completely released from spheronized granules in distilled water within 10 min. It can be concluded that spheroniged granule with ginseng extract could be packed in gelatin capsule since granules Possessed proper physical properties and quick release of saponin.

• Food Engineering Progress
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• v.14 no.2
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• pp.99-105
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• 2010

Proximate composition of whole hemp seed, paste viscosity of whole hemp seed pellets, bulk density, color, compression force, water solubility and absorption index and bowl life of whole hemp seed flakes manufactured by extrusion process were determined to evaluate whole hemp seed as flake additive. Extrusion process conditions were 35% of moisture content and 90, 100 and 110$^{\circ}C$ of barrel temperature. Content of moisture content, crude protein, crude fat, crude ash from whole hemp seed were 5.67${\pm}$0.02%, 25.93${\pm}$0.16%, 28.21${\pm}$0.56% and 7.70${\pm}$0.08%, respectively. The pellets hemp seed at 100 or 110$^{\circ}C$ had higher paste viscosity as compared to those pellet at 90$^{\circ}C$. The bulk density values of all hemp seed flakes were between 0.24 to 0.43 g/mL, depending on the barrel temperatures. The hardness of flake increased with decreasing percentage of hemp seed in flakes. An increase in barrel temperature from 90$^{\circ}C$ to 110$^{\circ}C$ resulted in increase of WSI and decrease of WAI. The bowl life of hemp seed flakes was increased from 5.8 to 15.5 min with the decrease in percentage of hemp seed. The highest overall quality was showed in flake added with 20% of hemp seed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.1
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• pp.32-36
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• 2021

This study was investigated in carbon diffusion behavior of laser-carburized TiZrN coating layer and the changes of mechanical properties. The carbon paste was deposited on TiZrN coatings, and the laser was irradiated to carburize into the coatings. The XRD peak corresponding to the (111) plane shifted to a lower angle after the carburization, showing the lattice expansion by doped carbon. The decreased grain size implied the compression by the grain boundary diffusion of carbon. The XPS spectra for the bonding states of carbon was analyzed that carbon was substitute to nitrogen atoms in TiZrN, as carbide, through the thermal energy of laser. In addition, the combination of sp2 and sp3 hybridized bonds represented the formation of an amorphous carbon. The cross-sectional TEM image and the inverse FFT of the TiZrN coating after carburizing were observed as the wavy shape, confirming the amorphous phase located in grain boundaries. After the carburization, the hardness increased from 34.57 GPa to 38.24 GPa, and the friction coefficient decreased by 83 %. In particular, the ratio of hardness and elastic modulus (H/E) which is used as an index of the elastic recovery, increased from 0.11 to 0.15 and the wear rate improved by 65 %.