• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.9_10
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• pp.1453-1464
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• 2007

The purpose of this study is to examine the hand of spring/fall fabrics for 'Saenghwal Hanbok' on subjective hand, objective hand and the preference. In this study, 28 varieties of spring/fall fabrics such as cotton fabrics, synthetic fabrics, blended fabrics and a silk fabric for 'Saenghwal Hanbok' are used. To evaluate the subjective hand of fabrics, the holistic touch and preferences, 33 seven ranks' segmentic differential scale questions are developed with adjective pairs and are gathered by surveying experts on clothes. The mechanical properties, HV and THV of them are measured and calculated by KES-FB system. Through subjective hand, items could be classified into six hand expressions: 'bulky/extensibility', 'stiffness', 'feeling of weight', 'surface property', 'drapability' and 'moisture property'. Through mechanical properties, the results indicated that the character of cotton fabrics are slight flexible, tough, rough, uneven, a bit heavy, thick and low resilience on tensile and compression, and then those of synthetic fabrics, blended fabrics and a silk fabric are thin and light, smooth, flat and bulkless. In correlation on subjective evaluations and the preference for 'Saenghwal Hanbok', cotton fabrics mainly depend on 'surface property' and 'moisture property' and then synthetic fabrics, blended fabrics and a silk depend on 'bulky/extensibility' and 'surface property' In correlation on objective hand and the preference for 'Saenghwal Hanbok'. people aren't satisfied with low resilience. high stiffness and low drape.

• Journal of Fashion Business
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• v.12 no.6
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• pp.61-72
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• 2008

The UV-protection effect of green-tea dyed fabrics was reported in our previous studies. The chitosan was used as a natural mordant of cellulose fiber for green tea extract because chitosan is a natural bio-polymer. The increase in the UV protection property of summer cellulose fabrics, cotton and linen, upon the repetition of chitosan mordanting and green tea dyeing was observed. However, the physical property change would be followed by this repeated wet processing of the cellulose fabric. Therefore, the physical changes of the chitosan mordanted and green tea dyed cotton and linen fabrics were evaluated by KES-FB system. Tensile, shear, bending, compression, and surface characteristics were tested upon the repetition of mordanting and dyeing treatments. Linearity of tensile force increased in the treated cotton and linen samples. Tensile energy and resilience decreased in all treated fabrics. Shear stiffness increased in the treated cotton and linen in general. Shear hysteresis was increased in all cotton samples and some linen samples. In cotton, the bending rigidity in all treated cottons increased except C3G3. As the chitosan mordanting numbers increased, the bending rigidity tended to decrease. In linen, the bending rigidity and hysteresis increased in all treated samples. Compressional energy and resilience increased as the number of chitosan mordanting increased both in cotton and linen. This could be the result of the increase in thickness upon chitosan mordanting. Surface coefficient of friction increased in the treated cotton and linen in general. Surface roughness tended to increase in cotton.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3290-3299
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• 2000

Digital watermarking has similar concepts with channel coding thechnique for transferring data with minimizing error in noise environment, since it should be robust to various kinds of data manipulation for protecting copyrights of multimedia data. This paper proposes a digital watermarking technique which is robust to various kinds of data manipulation. Intellectual property rights information is encoded using a convolutional code, and block-interleaving technique is applied to prevent successive loss of encoded data. Encoded intelloctual property rithts informationis embedded using spread spectrum technique which is robust to cata manipulation. In order to reconstruct intellectual property rights information, watermark signalis detected by covariance between watermarked image and pseudo rando noise sequence which is used to einbed watermark. Embedded intellectual property rights information is obtaned by de-interleaving and cecoding previously detected wtermark signal. Experimental results show that block interleaving watermarking technique can detect embedded intellectial property right informationmore correctly against to attacks like Gaussian noise additon, filtering, and JPEG compression than general spread spectrum technique in the same PSNR.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.99-104
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• 2006

The Langmuir-Blodgett(LB) technique has attracted considerable interest in the fabrication of electrical and electronic devices. Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A linear relationship between the monolayer compression speed u and the molecular area Am. Compression speed a was about 30, 40, 50mm/min. Langmuir-Blodgett(LB)layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 9$\sim$21. Also, we then examined of the Metal-Insulator-Metal(MIM) device by means of I-V. The I-V characteristics of the device are measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Polymer(Korea)
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• v.34 no.5
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• pp.430-433
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• 2010

The gasket materials of for the lithium ion battery requires chemical resistance to electrolyte, electrical insulating, compression set, anti-contamination and low temperature property. To check the special characteristics of fillers which are applied to rubber for gasket, compound of EPDM, NBR and FKM (fluoro elastomer) were made by adjusting weights of carbon black and silica additive. Using these compounds, we had done tests of long-term stability against electrolyte, compression set and low-temperature property with considering operating condition of the lithium ion battery. From this test, we investigated the physical and chemical characteristics of rubber with using of carbon black and silica additive in each.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.27-32
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• 2004

Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A method for determining the dielectric relaxation time ${\tau}$ of floating 'monolayers on the water surface is presented. MDC floing across monolayers is analyzed using a rod-like molecular model. It is revealed that the dielectric relaxation time ${\tau}$ of monolayers in the isotropic polar orientational phase is determined using a liner relationship between the monolayer compression speed a and the molecular area Am. Compression speed a was about 30,40,50mm/min. LB layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film.The physicochemical properties of the LB films were examined by UV absorption spectrum, SEM and AFM. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 3~9. Also, we then examined of the MIM device by means of I-V characteristic of the device is measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Composites Research
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• v.13 no.1
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• pp.1-10
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• 2000

During the compression molding process of the continuous fiber-reinforced polymeric composites, two main problems such as fiber-matrix separation and fiber orientation are produced by the difference of flow velocity. Molded parts are lead to be nonhomogeneous and anisotropic. As the mechanical property of the products are dependent on the separation and orientation, it is important to research the fiber mat structure and molding condition. If the fiber mat structure is changed by the increment of needling, the separation decreases and after compression molding the orientation is easily aligned. As it were, the compression moldability is good. But the defects as tears, thin thickness are produced in the products. Therefore, it is important to clarify the moldability in relation to the usage of products and the expenses of produce on the actual process. Therefore we must make the measurement methods that can define the moldability of products. In this research, the effects of the fiber mat structure(NP = 0, 5, 10, 25, 50 punches/$cm^2$) and the mold geometry($r_p$ = 1, 25, 50 mm) on the moldability of products were discussed. We investigated the case of one-dimensional flow in order to obtain the degree of nonhomogeneity and the fiber orientation function. In result, we could gain the correlation coefficient of the continuous fiber-reinforced polymeric composites. Also we experimented on the cup-type compression molding which was appeared the wrinkle on the flange part by the complex stress condition in order to gain the degree of nonhomogeneity and area ratio. In result, the moldability of products was expressed as the correlation coefficient and area ratio.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.488-493
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• 2011

The Korean spine geometry and property data for researchers were made by KISTI and Catholic Institute for Applied Anatomy. We took whole spine CT, X-Ray, BMD scan for making high resolution cross-sectional spine images using more 20 donated cadavers(60 - 80 years). Then we constructed 3-dimensional volume model using serial CT images by Mimics software. The major morphometric parameters of vertebrae were measured. Mechanical motion and property data were obtained by the same cadavers using the DEXA for BMD and the spine simulator. The Korean spine geometry and property data could be used for research and development of medical device.

• Korean Journal of Materials Research
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• v.22 no.5
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• pp.227-236
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• 2012

Ionomer is a thermoplastic that is composed of covalent bonds and ionic bonds. It is possible to use this material in processes such as injection molding or extrusion molding due to the material's high oil resistance, weatherproof characteristics, and shock resistance. In this study, a new ionomer having a multifunctional group was prepared by a stepwise neutralization system with the addition of acidic and salt additives. In step I, to increase the contents of the multifunctional group and the acid degree in ethylene acrylic acid (EAA), MGA was added to the ionomer resin (EAA). A new ionomer was prepared via the traditional preparation method of the ionic cross-linking process. In step II, metal salt was added to the mixture of EAA and MGA. The extrusion process was performed using a twin extruder (L/D = 40, size : ${\varphi}30$). Ionomer film was prepared for evaluation of gas permeability by using the compression molding process. The degree of neutralized and ionic cross-linked new ionomer was confirmed by FT-IR and XRD analysis. In order to estimate the neutralization of the new ionomer film, various properties such as gas permeation and mechanical properties were measured. The physical strength and anti-scratch property of the new ionomer were improved with increase of the neutralization degree. The gas barrier property of the new ionomer was improved through the introduction of an ionic site. Also, the ionic degree of cross-linking and gas barrier property of the ionomer membrane prepared by stepwise neutralization were increased.

• Journal of Mechanical Science and Technology
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• v.19 no.6
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• pp.1229-1242
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• 2005

When natural rubber is used for a long period of time, it becomes aged; it usually becomes hardened and loses its damping capability. This aging process affects not only the material property but also the (fatigue) life of natural rubber. In this paper the aging effects on the material property and the fatigue life were experimentally investigated. In addition, several fatigue life prediction equations for natural rubber were proposed. In order to investigate the aging effects on the material property, the load-stretch ratio curves were plotted from the results of the tensile test, the compression test and the simple shear test for virgin and heat-aged rubber specimens. Rubber specimens were heat-aged in an oven at a temperature ranging from $50^{\circ}C$ to $90^{\circ}C$ for a period ranging from 2 days to 16 days. In order to investigate the aging effects on the fatigue life, fatigue tests were conducted for differently heat-aged hourglass-shaped and simple shear specimens. Moreover, finite element simulations were conducted for the specimens to calculate physical quantities occurring in the specimens such as the maximum value of the effective stress, the strain energy density, the first invariant of the Cauchy-Green deformation tensor and the maximum principal nominal strain. Then, four fatigue life prediction equations based on one of the physical quantities could be obtained by fitting the equations to the test data. Finally, the fatigue life of a rubber bush used in an automobile was predicted by using the prediction equations, and it was compared with the test data of the bush to evaluate the reliability of those equations.