• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.2
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• pp.13-24
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• 1999

Electronic cash is a digital signature issued by bank. If the concept of the distributed secret sharing and magic ink signature is introduced in the existing electronic cash system we can increase the security level and the availability of electronic cash system and trace the electronic cash itself and the owner of electronic cash which was issued anonymously to a user in case of illegal usage of electronic cash by users. If the trust is concentrated on one bank system. the problem of misuse of bank can be occurred. To solve this problem, the distributed secrete sharing scheme need to be introduced in electronic cash system. In this paper We propose a DSS(Digital Signature Standard) distributed magic ink signature scheme and a KCDSA(Korea Certificate-based Digital Signature Algorithm) distributed magic ink signature scheme using a verifiable secret sharing method. and we compare two methods with respect to the required computation amount for the generation of magic-ink signature.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.573-577
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• 2013

The one of the most important issue in roll-to-roll gravure printing is increase of ink transfer ratio or printability. As the result of high ink transfer ratio or printability, we can assess the quality of the printed patterns. The rheological properties are the important factors for the printability of electrodes patterning. In this study, the rheological properties of conductive ink are controlled by adding the solvent. The inks with different rheological properties are used for the patterning of the electrodes of $100{\mu}m$ by gravure printing equipment. The various printing speed, which also affect the rheological properties of conductive ink, is applied and the printed patterns are compared for their width and aspect ratio. Decreasing in the ink viscosity as well as increasing in the printing speed decreases the printability in gravure patterning, which shows that the rheological properties are important factors for the printability of gravure patterning.

• Analytical Science and Technology
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• v.29 no.1
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• pp.35-42
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• 2016

A new nano-composite carbon ink for the development of disposable dopamine (DA) biosensors based on screen-printed carbon electrodes (SPCEs) is introduced. The method developed uses SPCEs coupled with a tyrosinase modified nano-composite carbon ink. The ink was prepared by an “in-house” procedure with reduced graphene oxide (rGO), Pt nanoparticles (PtNP), and carbon materials such as carbon black and graphite. The rGO-PtNP carbon composite ink was used to print the working electrodes of the SPCEs and the reference counter electrodes were printed by using a commercial Ag/AgCl ink. After the construction of nano-composite SPCEs, tyrosinase was immobilized onto the working electrodes by using a biocompatible matrix, chitosan. The composite of nano-materials was characterized by X-ray photoelectron spectroscopy (XPS) and the performance characteristics of the sensors were evaluated by using voltammetric and amperometric techniques. The cyclic voltammetry results indicated that the sensors prepared with the rGO-PtNP-carbon composite ink revealed a significant improvement in electro-catalytic activity to DA compared with the results obtained from bare or only PtNP embedded carbon inks. Optimum experimental parameters such as pH and operating potential were evaluated and calibration curves for dopamine were constructed with the results obtained from a series of amperometric detections at −0.1 V vs. Ag/AgCl. The limit of detection was found to be 14 nM in a linear range of 10 nM to 100 µM of DA, and the sensor’s sensitivity was calculated to be 0.4 µAµM⁻¹cm⁻².

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.726-730
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• 1999

To investigate the deinkability according to the ink composition, deinking chemicals and aging time, newspaper was printed with different solvent types: 30% soy-based oil ink(A), 50% soy-based oil ink(B), 45% mineral oil ink(C) and 42% linseed oil ink(D). The newspapers were aged naturally for 15, 30, 90, 180 days, and were deinked with various deinking chemicals. The brightness of the deinked pulp of newspaper was affected by the ink composition, aging time and deinking chemicals, i.e., it was decreased with increasing aging time in the order of C, A, B and D. And the brightness also decreased in the order of lipase, cellulase and conventional chemical. The deinking yield showed the same tendency as the brightness variation at a given brightness. The strength of the deinked pulps increased until 30 days, but decreased or maintained after that time. And the strength decreased in the order of C, D, B and A, and also decreased in the order of lipase, conventional chemicals and cellulase.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.320-325
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• 2007

Promoter hypermethylation of the $p16^{INK4a}$ gene was investigated in 52 sets of samples of tumor tissue and adjacent normal tissue from Korean patients with colorectal cancer, using the proposed modified the Real-time PCR/SYBR Green detection method presented in this study. In normal tissue, 29 of 52 patients (56%) were methylated and in tumor tissue, 23 of 52 patients (44%) were methylated. The 34 cases (65.4%) showed a concordant DNA methylation pattern in both normal tissue and tumor tissue. Analyzing the association between the clinicopathologic features and DNA methylation status of the $p16^{INK4a}$ gene, the DNA methylation status according to by Duke's stage was different while other clinicopathological characteristics, including the age, sex, tumor stage, and histologic type of the patient were not found to be correlated with $p16^{INK4a}$ methylation. With multivariate logistic regression, it was observed that the DNA methylation status of $p16^{INK4a}$ gene in normal tissue was correlated with the DNA methylation status of the $p16^{INK4a}$ gene in tumor tissue (P=0.026). According to a Kaplan-Meier survival analysis, a difference in the survival rate by DNA methylation status was found, but it was not significant.

• Journal of the Korean Graphic Arts Communication Society
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• v.31 no.1
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• pp.15-37
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• 2013

Split digital printing into interior and outdoors on present advertisement. When is printing machine for interior mainly, use ink of water-based type. Equipment of this type embodies high resolution, but ink special quality light stability is weak. Also, when is printing machine for outdoors, printing machines of solvent or UV type are used because of water resistance and light stability. This printing machines hard to embody ink special quality high resolution mainly. And because outside is far visibility range, is uncommon in case high resolution requires embodiment. Therefore, high resolution of inside is water-based type considering this item and outside printing machine of low resolution solvent type mainly announce. Also, divide into eco-friendly latex ink type that is announced to water-based, solvent, UV according to ink type and the latest market using in occasion of digital printing machine used as advertisement industry. Color management that is been consistent of original image has a lot of difficulties by using substrate that is also various to digital printing machine for such various advertisement. But, consumers is rising realization about color or desire about quality improvement of color gradually in interior outside advertisement market. So, require solution method. Therefore, in this paper, eco-friendly ink use applied device calibration through linearization in done latex digital printing machine to basis. And studied right color management plan of digital printing for interior outside advertisement through three steps such as G7 calibration application and ICC profile application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.892-898
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• 2008

3D rapid prototyping is the manufacturing technology to fabricate a prototype with the data stored in a computer, which differs from conventional casting technology in terms of an additive process. Various 3D rapid prototyping techniques such as stereolithograpy. fused deposition modeling. selective laser sintering, laminated object manufacturing have been developed but among them, 3D inkjet printing has a unique feature that materials could be jetted to directly form the body of a prototype, which could be a finished product functionally and structurally. However, this needs ink with a high solid content, which tends to increase the dynamic viscosity of ink. The increase of ink viscositytends to restrict the jettable range of ink and hence the jetting conditions should be optimized. The intrinsic speed of sound in a hot melt ink with ceramic nanoparticles dispersed is one of key components to determine the jettable range of ink. In this paper, the way to measure the intrinsic speed of sound in a hot melt ceramic ink is proposed and its influence on the jetting condition is discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.272-272
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• 2010

We have fabricated alumina thick films by inkjet printing technology. Two different types of ink system were formulated in order to understand their evaporation behaviors and their evaporation effects on the powder distribution on, the surface during inkjet-printed alumina thick films. Single solvent system was formulated with N,N-dimethylformamide(DMF), which led to coffee ring effects which non-uniformly distributed alumina particles on the substrate during the ink evaporation. However, Co-solvent system which consists of both Water and DMF produced relatively uniform distribution of the particles on the substrate. We believe that these two different distributions of alumina particles are attributed to the ink fluid flow directions in the ink droplets ejected from the different ceramic ink system. We have modulated inkjet parameters such as dot-to-dot distance, line-to-line distance, jetting velocity and jetting drop size in order to find out the optimum condition for the printing of alumina thick films from two different ink systems. The surface roughness, microstructures and dielectric properties of these inkjet-printed alumina thick films were investigated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.2 s.110
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• pp.38-46
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• 2005

Experimental work was carried out in order to produce a novel grade of ink-jet paper that has both high print-out quality and price competitiveness. Usually, silica and PVOH has been used for ink-jet paper to design the coating layer that has a hydrophilic and micro-porous structure. However, poor rheological characteristics and low productivity of the silica-PVOH system make the price of the ink-jet paper high. The main focus of this study was replacing the conventional silica (coating pigment) PVOH (binder) coating system with the new PCC (coating pigment) cationic starch (binder) coating system, and optimizing thecoating technology associated with PPC-cationic starch system. In this study, ink-jet print quality of PCC-coated papers was compared with that of silica-coated paper. Two types of PCC were used: conventional type and colloid type. It turned out that PCC C, a conventional coating pigment, has not given a desirable result: it showed high dot reproduction, but it gave low optical density. In spite of low dot reproduction, the qualities of PCC A were comparable or superior to those of silica in optical density, color reproduction, and the uniformity of printing surface. It was also shown that the problems that are happened when the dosage level of cationic starch was too low were varied with ink-type used in each printer. However, in the case of low binder level, the produced image was widely spread resulting fromtoo low optical density of images, or from the lack of bonding ability to set ink into coating surface.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.348-355
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• 2013

Squid ink was added to the salt fermented squid by 2% or 4% of concentration and ripened at $10^{\circ}C$ for 8 weeks and at $20^{\circ}C$ for 32days. The effects of the squid ink on the amino nitrogen and muscle protein of salt fermented squid were investigated. The results are as follows; As the salt concentration was decreased and the fermentation temperature raised, amino nitrogen in the salt fermented squid without addition of the squid ink was significantly increased to the latter stage of the ripening and hence fermentations were enhanced. From the change of the protein in the squid muscle in the experiments, dissolution of the myosin heavy chain took place conspicuously in the early stage of the ripening while actin was rarely changed which resulted in the strong resistance to protease. The amino nitrogen content in the salt fermented squid addition of the squid ink has increased to the latter part of the ripening but the range was smaller than no treatment groups. The protein in squid muscle, especially the myosin heavy chain was remarkably dissolved in the middle of the ripening whereas the squid ink added groups of high salt concentration and low temperature showed the tendency of slow proteolysis.