• Journal of applied mathematics & informatics
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• 제27권5_6호
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• pp.1049-1059
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• 2009

Continuous t-norm based shape preserving additions of LR-fuzzy intervals with unbounded support is studied. The case for bounded support, which was a conjecture suggested by Mesiar in 1997, was proved by the author in 2002 and 2008. In this paper, we give a necessary and sufficient conditions for a continuous t-norm T that induces DR-shape preserving addition of LR-fuzzy intervals with unbounded support. Some of the results can be deduced from the results given in the paper of Mesiar in 1997. But, we give direct proofs of the results.

• 한국세라믹학회지
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• 제34권12호
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• pp.1221-1226
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• 1997

The effects of sintering atmosphere and dopant addition on the behavior of densification and grain growth of SnO2 ceramics were investigated with consideration of defect chemistry. CoO and Nb2O5 were chosen as dopants, and oxygen and nitrogen were used for controlling of sintering atmospheres. With the decrease of oxygen partial pressure, densification was depressed due to evaporation of SnO2 ceramics. In the case of SnO2 sintering, the addition of CoO, which produced oxygen vacancy in SnO2 ceramics, led to acceleration of densification and grain growth. On the contrary, when Nb2O5 as a dopant producing Sn vacancy was added to SnO2 ceramics, densification and grain growth were simultaneously retarded. As results, it was conformed that diffusion of oxygen ions was rate determinant in densification and grain growth of SnO2 ceramics.

• 한국주조공학회지
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• 제15권6호
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• pp.588-595
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• 1995

SiC particles reinforced Mg-Zr, Mg-Zn and Mg-Zn-Zr composites were manufactured by Rheocompocasting method. Effects of Zn, Zr addition on microstructures and hardness were investigated by using the micro Vickers hardness tester, the optical and scanning electron microscopy. By the Zr addition to the pureMg/SiCp composites, SiC particles become more homogeneously dispersed and grain refined so that the micro hardness of the composite increased. In case of Zn addition, although grain refinement and homogeneous dispersion effects of SiC particles were not obtained, hardness was more increased than the only Zr added composite by the formation of many Mg-Zn intermetallic compounds at grain boundary. In the Mg-Zn-Zr/SiCp composite, the highest value of hardness was obtained by triple effects such as grain refining, dispersion hardening of SiC particles and Mg-Zn compounds.

• 한국세라믹학회지
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• 제35권4호
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• pp.339-346
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• 1998

Active belite cement clinkers were synthsized by using natural raw materials with borax and calcium phosphate ({{{{ {Ca }_{3 }( {PO}_{4}) }}2) In both case {{{{alpha ^、 {C }_{2 }S }} were formed but borax was more efficient. The cement syn-thesized with the addition of borax was hydrated with the addition of anhydrite(5 wt%) and slag(30wt%, 40wt% 50wt%) The addition of 50wt% slag with anhydrite was good for strength development in 7days and the compressive strength was developed to twice than no addition of slag at 28 days strength.

• 한국세라믹학회지
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• 제28권5호
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• pp.347-352
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• 1991

The effects of Ta2O3 doping on the microstructure, electrical properties and thermal expansion in Pb(Zr0.525Ti0.475)O3 ceramics were studied. Density, average grain size, electromechanical coupling factor kp and thermal expansion coefficient of unpoled and poled samples were measured as a function of Ta2O5 content. Average grain size was decreased and density increased above 0.6 mol% Ta2O5 addition. In case of 0.2 mol% addition, density showed minimum according to grain growth. Dielectric constant and electromechanical coupling factor kp were the lowest in 0.2 mol% addition increased with Ta2O5 addition.

• Bulletin of the Korean Chemical Society
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• 제15권3호
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• pp.193-197
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• 1994

Due to possibility of visual observation of phase transformations and processes during solidification, the transparent binary alloy models are important in materials and metallurgical sciences. As such, phase diagram, linear velocity of crystallization, microstructure and spectral behaviour of binary organic systems of benzidine with resorcinol and catechol involving formation of addition compound with congruent melting point have been studied. While their phase diagrams show the formation of two eutectics and a 1:2 (B:RC, B:CT) addition compound in each case, the crystallization data obey the Hillig-Turnbull equation. The microstructural investigations give the characteristic morphology of the eutectics and the addition compounds, the spectral studies suggest intermolecular hydrogen bonding between two components forming the molecular complex.

• 대한수학회지
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• 제46권4호
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• pp.859-893
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• 2009

In this article, we will characterize structures of geometric quotient orbifolds of G-manifold of genus two where G is a finite group of orientation preserving diffeomorphisms using the idea of handlebody orbifolds. By using the characterization, we will deduce the candidates of possible non-hyperbolic geometric quotient orbifolds case by case using W. Dunbar's work. In addition, if the G-manifold is compact, closed and the quotient orbifold's geometry is hyperbolic then we can show that the fundamental group of the quotient orbifold cannot be in the class D.

• The Korean Journal of Pain
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• 제2권1호
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• pp.42-44
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• 1989

The present case of acute and severe pneumothorax during celiac plexus block appears to be an extremely rare occurrence. In this case, the rudimentary 12th rib in addition to the sacralization of the 5th lumber vertebra are the most likely causes of the inadvertent misplacement of the needle.

• Journal of Chest Surgery
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• 제29권11호
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• pp.1284-1287
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• 1996

결핵성 림프절염의 합병증으로 생기는 식도기관지루는 드물고, 항결핵제의 투여와 함께 외과적 치료를 보통 필요로 한다. 본 증례는 결핵성 식도기관지루를 항결핵제 단독으로 투여하여 성공적으로 치유된 예이다.

• 셀메드
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• 제12권5호
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• pp.2.1-2.3
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• 2022

Objective: A case report on the improvement of gallbladder polyps through Ortho-Cellular Nutrition Therapy Methods: On ultrasound, gallbladder polyps were detected in a 54-year-old male Korean patient. In addition to the polyps, there were also calcific tendonitis and various inflammatory conditions of the shoulder. Results: Ultrasound revealed the absence of gallbladder polyps 8 months after nutritional therapy. Conclusion: It is believed that nutritional therapy is beneficial for patients with gallbladder polyps who do not require surgical treatment and are under observation.