• Textile Coloration and Finishing
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• v.4 no.3
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• pp.116-121
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• 1992

This paper is on for a material to replace the petroleum-based resins used as adhesives for the fiber in rubber composite materials. The study limited to the reaction properties of tannin with formaldehyde. Tannin-formaldehyde(TF) reactions were carried out in aqueous media. Rates of reaction were strongly dependent on concentration, temperature, pH, and the mole ratio of tannin to formaldehyde. Viscosities of reaction mixtures were followed up to gelation. The reactivity of tannin-formaldehyde resins was greater than that of resorcinol-formaldehyde resins. To formulate an adhesive, a styrene-butadiene-vinyl pyridine terpolymer latex(L) was added to the TF. This preliminary results suggest that the condensed tannins have considerable promise as substitutes for resorcinol used in resin formulation for bonding of fiber to rubber.

• Journal of Applied Reliability
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• v.11 no.4
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• pp.399-407
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• 2011

Reliability evaluation of One-Shot system which flies at speed of Mach must be evaluated as the result of many firing tests. But many firing tests are impossible because of budget deficit. Consequently the reliability prediction which substitutes firing tests is used. The accuracy of reliability prediction is decided according to a quantity of accumulated test data. If the test data is insufficient, the direction of prediction can not be set. So we propose the reliability prediction method which applies MIL-HDBK-217 Plus. MIL-HDBK-217 Plus is described about reliability prediction method without sufficient test data. So we apply MIL-HDBK-217 Plus to the rocket motor system, and we accomplish a modeling and a reliability prediction about the system.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.171-181
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• 2017

This paper summarizes the study on effect of ceramic waste powder as partial substitute to cement in binary blend and along with silica fume in ternary blend high strength concrete in normal and aggressive environments. Strength parameters such as compression & tension and durability indices such as corrosion measurement, deterioration, water absorption and porosity were studied. Ceramic waste powder was used in three different percentages namely 5, 10 and 15 with constant percentage of silica fume (1%) as substitutes to cement in ternary blend high strength concrete was investigated. After a detailed investigation, it was understood that concrete with 15% ceramic waste powder registered maximum performance. Increase of ceramic waste powder offered better resistance to deterioration of concrete.

• Journal of the Korean Professional Engineers Association
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• v.30 no.6
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• pp.59-67
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• 1997

As Information society evolves, there is a growing need that substitutes agents for users to do the given Jobs in distributed computing environments. Agents can retrieve and browse the diverse information via Internet, as the users request, and can deal with the complicated routine jobs on behalf of users with timeliness and efficiency. Especially, mobile agent can support the paradigm for distributed application programs in Internet environments. This is suitable to jump-to-jump model without any hesitations because agent moves. Agents can be applied to various applications, but we restrict it to market information retrieval in this paper. On recognizing a query about merchandise information by an user, agent by itself retrieves the corresponding information by navigating the Internet and informs the result to the user. In this paper, we review the mobile agent configuration to do this kind of work, propose the system architecture based on this review. By using this system, users can be free from complicated routine jobs and pursue his/her wishes to promote ones welfare.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.303.2-304
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• 2003

For the purpose of obtaining high bone forming efficacy, chitosan microgranules were developed as bone substitutes. Chitosan has been applied to conduct the extracellular matrix (ECM) formation in tissue regenerative therapy. Microgranules designed in this study confer drug releasingcapacity in bone defect over long period to enhance bone regeneration. (omitted)

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.54.2-54.2
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• 2011

DTBP (dimethyl 3,3`-dithiobispropionimidate) was applied to collagen and gelatin coating on BCP granules and a crosslinking agent. The DTBP crosslinking was done for decreasing the solubility of the coating and hence increasing the stability. The nanostructure of collagen and gelatin coating surfaces were observed by SEM technique. Based on the DSC thermograms and FT-IR spectrums, the crosslinkings were confirmed between collagen molecules and gelatin molecules. The compressive strength was measured before crosslinking and after that. In-vitro study was carried out by measuring cell viability and observing cell morphology after DTBP crosslinking. Moreover, the proliferation ability of MG-63 osteoblast-like cells on the crosslinked BCP granules was evaluated by Western blot assay. The BCP granules were implanted into rabbit femur for 4 weeks and 12 weeks. The bone tissue formation was analyzed with micro-computed tomography (micro-CT) and histological analysis was also carried out by hematoxylin and eosin (H&E) staining for visualization of cells.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.06a
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• pp.115-119
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• 1998

Possibilities of substitution was investigated in the Langadite({{{{ {La }_{3 } {Ga }_{ 5}{SiO }_{14 }}}}}) system.{{{{{TiO}_{2 }}}}} was substitutes for{{{{{SiO}_{2 }}}}} followed by the substitution of{{{{{Nd}_{2 }{O}_{3}}}}}fo{{{{{La}_{2 }{O}_{3}}}}}. An effort to replace GeO2, which is reported to have been substitution for{{{{{SiO}_{2 }}}}} in the Langasit e system, for{{{{{TiO}_{2 }}}}} i n{{{{{ Nd}_{ 3} {Ga }_{5 } {TiO }_{14 } }}}} was also undertaken. In another experiment,{{{{{ Y}_{ 2}{ O}_{3 } }}}} was substituted for{{{{{ La}_{2 } {O }_{ 3} }}}}. All of substitution possibilities were investigated through solid state reactions and analyzed with XRD. Further analysis was carried out with an SEM. Lastly, the dielectric constants of the sintered body were measured.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.33-36
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• 2006

In manufacturing Ultra high strength fiber reinforced concrete(UHSFRC), steel fiber, super-plasticizer and silica fume are important but they are imported materials therefore very expensive. consequently it is necessary to find substitutes of them or to develop producing techniques in order to manufacture UHSFRC economically. In this study, we investigated if it was possible to substitute blast-furnace slag instead of silica fume and steel fiber of home manufacture instead of one of overseas manufacture.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.79-80
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• 2009

Compression stress distribution used to concrete structure design substitutes equivalent rectangle, trapezoid and parabola-rectangle stress block for actual concrete stress distribution. Presently, rectangular stress block of Korea Concrete Design Code is equal to it of ACI code that doesn't reflect the material feature of the high strength concrete. The study does an experiment on concrete compression stress distribution to know the material feature of the concrete used in korea.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.579-583
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• 2001

In the area of data clustering in high dimensional space, one of the difficulties is the time-consuming process for computing vector similarities. It becomes worse in the case of the agglomerative algorithm with the group-average link and mean centroid method, because the cluster similarity must be recomputed whenever the cluster center moves after the merging step. As a solution of this problem, we present an incremental method of similarity computation, which substitutes the scalar calculation for the time-consuming calculation of vector similarity with several measures such as the squared distance, inner product, cosine, and minimum variance. Experimental results show that it makes clustering speed significantly fast for very high dimensional data.