• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.125-127
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• 1996

This paper deals with the fabrication of 4 poles anisotropic Sr·ferrite plastic magnets. After Polyamide6 and polyamlde12 are kneaded respectively with Sr·ferrite powder, silane coupling and calcium stearate of lwt% are added for coating and pelleting. The pelleted specimen are injection-moulded under the magnetic field using 4 poles mould. For 4 poles anisotropic Sr·ferrite plastic magnets with polyamide6 as a binder, the surface magnetic flux density distribution is +943.8∼-943.87kG and the deviation is 5.2%, where as with polyamide12, the distribution is +1040.9∼-1040.9kG and the deviation is 5.4%. It shows that both of the magnet distributions are stable. As the results of the experiments, we find 4 poles anisotropic Sr·ferrite magnets have good properties as the materials appropriate for manufacturing magnet type synchronous motors.

• Transactions on Electrical and Electronic Materials
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• v.6 no.3
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• pp.128-132
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• 2005

In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel (STS304) tube applying magnetic abrasive polishing. Either white alumina (WA) or green carborundum (GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than $40\%$ of improvement of surface roughness was achieved when WA grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with WA or GC grains.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1623-1625
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• 1998

At present, in case of circular conductor, various water blocking methods are in use for power cable. But, in case the shape of the conductor is sector shaped, segment conductor it was very difficult to make the water blocking segment conductor. This paper describes the developement details of the water blocking segment conductor applied with swellable powder.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.527-529
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• 1997

In this paper, a system to control feeding rate by fuzzy controller was developed and tested in the various raw material of the powder gram state. The designed fuzzy controller for feeding rate control system is proved robust performance under parameter variation and load disturbance effect which is caused by the kind and quantity of various raw material.

• Journal of the Korean Ceramic Society
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• v.34 no.8
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• pp.797-802
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• 1997

The use of carbon materials in mechanical components such as bearings, seals, and bushings that do not require lubricants is increasing rapidly. This paper reports on establishing the optimal condition for resin-bonded carbon materials. We fixed the content ratio of materials, which include graphite powder and diatomite as a lubricant modifier and a friction modifier, respectably, with resin used as a bonding material. We then produced bushings using hot-pressing within the temperature range of resin curing. The properties of bushing, the friction coefficient, wear rate and the mechanical strengths are discussed in relation to the content of respective materials, with correlation of friction coefficient and sliding distance. Finally, we examined the friction coefficient changes according to the applied load on bushing and the friction coefficient changes according to contact speed of bushing.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.82-87
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• 2004

The purpose of this paper is to obtain the data for manufacturing of microbe carriers as a method of FRP waste recycling technology. Since FRP waste is polymer, the experiment of the thermogravity analyzing was carried out to find thermal behavior. After that, microbe carriers were prepared from waste FRP powder, which had been decomposed, milled, and mixed with clay as a binder and CaCO3 as a flux and a loaming agent, respectively. finally it was made by filing of the sample up to 1,05$0^{\circ}C$. It was investigated how the variation of the additives and firing temperature effect apparent density, water absorption and micro structure.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.1
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• pp.19-29
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• 1994

In this paper a review of literature on Nuruk(yeast) between 1907 and 1945 was made, which showed that barley, rice bran, oat, rye, and other ingredients were originally used according to region and production quantity. Yeast can be classified into rough (Chokuk) and powder (Bunkuk) types depending on the degree of grinding. Yeast also had seasonal names, being called " Choonkuk", Hakuk", Jeolkuk", and "Dongkuk" in the spring, summer, autumn and wither respectively. The form of yeast in terms of quantity, size, and shape varied greatly by region, Production facilities were composed of plant structures to suit each process, enabling continuous output. The production process included shaping, placement in the fermenting chamber, piling by turns, risk-sifting and final output. Testing procudures were divided into visual inspection, physical testing, and chemical analyses.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.473-476
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• 2005

Silica fume has merits of filling the voids, enhancement of reheological chracteristics, prduction of secondary hydrates by pozzolanic reaction in reactive powder concretes. However silica fume has been imported in high-cost in domestic industry, we need to investigate replaceable material in stead of silica fume in a view of economy Therefore, in this paper, in order to investigation replacement of silica fume in ultra-high strength SFRCC we used another mineral admixtures like that fly-ash, blast slag.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.221-224
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• 2005

In order to traffic safety during winter season, snowfall and cold area has been spread the deicing chemicals, and the spraying amount is increasing every year. Use of deicing chemicals has been and will continue to be a major part of highway snow and ice control methods. Chloride-containing chemicals such as calcium chloride or rock salt are main deicers for the road. Extensive use of chloride deicers is, however, the source of substantial cost penalties due to their corrosive action and acceleration to deterioration concrete structures. Deterioration due to de-icer salt occurs in practice in concrete pavement, dike, barrier and similar structure. This paper reports the results of effect of de-icer salt on durability of concrete structure in winter. To protect concrete structure from damage by de-icer salt in winter, the exposure test was performed using three methods such as increase in design strength upto 35MPa application of granulated blast furnace slag powder, and concrete sealer. Of these, the method of increase in design strength upto 35MPa showed better durability for deterioration by de-icer salt.

• Journal of the Korean Ceramic Society
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• v.54 no.6
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• pp.470-477
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• 2017

Ceramic processing to fabricate 3D complex ceramic structures is crucial for structural, energy, environmental, and biomedical applications. A unique process is ceramic stereolithography, which builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This approach directly writes layers in liquid ceramic suspension and allows one to fabricate ceramic parts and products having more accurate, complex geometries and smooth surfaces. In this paper, both UV curable materials and processes are presented. We focus on the basic material principles associated with free radical polymerization and rheological behavior, cure depth and broadening of cured lines, scattering at ceramic interface and their corresponding simulation. The immediate potentials for ceramic AM to change industry fabrication are also highlighted.