• Metals and materials international
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• 제24권6호
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• pp.1309-1314
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• 2018

In this study, we investigated the state of $Y_2O_3$, as a major additive element in Fe-based ODS alloys, during mechanical alloying (MA) processes by thermodynamic approaches and experimental verification. For this purpose, we introduced $Ti_2O_3$ that formed different reaction products depending on the state of $Y_2O_3$ into the Fe-based ODS alloys. In addition, the reaction products of $Ti_2O_3$, Y, and $Y_2O_3$ powders were predicted approximately based on their formation enthalpy. The experimental results relating to the formation of Y-based complex oxides revealed that $YTiO_3$ and $Y_2Ti_2O_7$ were formed when $Ti_2O_3$ reacted with Y; in contrast, only $Y_2Ti_2O_7$ was detected during the reaction between $Ti_2O_3$ and $Y_2O_3$. In the alloy of $Fe-Cr-Y_2O_3$ with $Ti_2O_3$, $YTiO_3$ (formed by the reaction of $Ti_2O_3$ with Y) was detected after the MA and heat treatment processes were complete, even though $Y_2O_3$ was present in the system. Using these results, it was proved that $Y_2O_3$ decomposed into monoatomic Y and O during the MA process.

• 이베로아메리카
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• 제12권1호
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• pp.55-86
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• 2010

Después de la década 1990, la soja ha sido un agro-producto más importante en Paraguay. Pero la soja ha convertido el campo rural en la zona de la producción, es decir, la zona de sojización, para la exportación. Por otro lado, el campo rural se ha deteriorado por el aumento de la extensión del cultivo sojal. Los cultivos se extienden a lo largo de cientos de kilómetrios y afectan zonas muy cercanas a comunidades, colonias y otros asentamientos campesionos e indígenas, incluyendo escuelas, hogares, charcas familiares y comunitarias. Los sojeros utilizaron los agrotóxicos que contaminaron la tierra, agua y alimentos. Aunque los campesinos no quieren vender sus tierras, no ven otras alternativas ante los graves problemas que conllevan las masivas fumigaciones. Ellos venden sus lotes y migraron a ciudades. Se pierde la soberanía territorial, pues las tierras pasan a manos extranjeras, y la soberanía alimentaria, porque se desplaza la diversificación y los cultivos de subsistencia, expulsando a los campesions hacia las ciudades. Ante el agravamiento de la situación causado por el incremento del cultivo de la soja, los campesinos empezaron a resistir, es decir, desarrollar 'la guerra de la soja' contra los sojeros y el gobierno paraguayo que no tenia refuerzos de resolver los problemas. Los campesinos formaron coordinadoras por la defensa de sus tierras y de su modo de vida contra los sojeros. Las luchas y movilizaciones reclaman no sólo un nuevo tipo de reforma agraria sino también la defensa de la soberanía económica, alimentaria y territorial, el derecho a producir con la propia semilla y a desarrollar técnicas agrícolas adecuadas de acuerdo con la economía campesina y el equilibrio del medio ambiente, el desarrollo de formas sociales de producción y la democratización en el medio rural.

• 대한의생명과학회지
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• 제29권4호
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• pp.302-313
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• 2023

Y chromosomal short tandem repeat (Y-STR) markers have been developed continuously to complement forensic DNA analyses and population genetic studies. Initially, we collected data from previously reported Korean population Y-STR haplotype studies on 1133 individuals. We then conducted a marker expansion analysis using a dataset from the Y-STR Haplotype Reference Database (YHRD), covering up to 29 Y-STRs, referred to as Ymax. Additionally, we examined the impact of rapidly mutating (RM) Y-STRs included in this expanded marker set on the discrimination capacity. We observed that marker expansions both with (0.9896), and without (0.9510), RM Y-STR improved the discrimination capacity. Subsequently, we focused on 16 individuals belonging to seven distinct groups sharing identical haplotypes. These particular haplotypes had been previously identified among 476 unrelated males using 23 Y-STR markers from the PowerPlex^® Y23 System. We expanded the marker panel up to Ymax to explore how discrimination improved with an expansion of Y-STR markers for these 16 individuals. Among the expanded markers, DYS627, which had high discriminatory power, had a high mutation rate (1.10 × 10^-2) and high gene diversity (0.83). In contrast, DYF387S1 displayed high gene diversity (0.95) but a relatively low mutation rate (2.80 × 10^-3). We propose that these findings will be valuable in the selection of suitable Y-STR markers, depending on the objectives of forensic analyses. Additionally, the presence of frequently observed Y-haplotypes in Korean population will facilitate statistical interpretation in Y-STR DNA profiling.

• 충청수학회지
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• 제9권1호
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• pp.11-15
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• 1996

In this paper we prove that if Y is a poset of the form $\underline{1}{\oplus}Y^{\prime}$ for some subposet Y' then BCK(Y) is a ${\Gamma}$-BCK-algebra. Moreover, if X is a BCI-algebra then Hom(X, BCK(Y)) is a positive implicative ${\Gamma}$-BCK-algebra.

• 호남수학학술지
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• 제37권4호
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• pp.473-486
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• 2015

In this paper, we investigate a stability problem for a functional equation f(-x - y - z) - f(x + y) - f(y + z) - f(x + z) + 2f(x) + 2f(y) + 2f(z) - f(-x) - f(-y) - f(-z) = 0 by applying the direct method.

• 대한수학회지
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• 제33권2호
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• pp.217-225
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• 1996

An orthomodular lattice (abbreviated by OML) is an ortholattice L which satisfies the orthomodular law: if x $\leq$ y, then $y = x \vee (x' \wedge y)$ [5]. A Boolean algebra B is an ortholattice satisfying the distributive law : $x \vee (g \wedge z) = (x \vee y) \wedge (x \vee z) \forall x, y, z \in B$.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1993년도 학술대회지
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• pp.124-126
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• 1993

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.173-174
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• 2009

• East Asian mathematical journal
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• 제35권3호
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• pp.351-356
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• 2019

In this paper, we investigate Hyers-Ulam-Rassias stability of the general quartic functional equation f(5x + y) - 5f(4x + y) + 10f(3x + y) - 10f(2x + y) + 5f(x + y) - f(y) = 0.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제13권4호
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• pp.295-301
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• 2006

We Investigate the relation between the multi-variable bi-additive functional equation f(x+y+z,u+v+w)=f(x,u)+f(x,v)+f(x,w)+f(y,u)+f(y,v)+f(y,w)+f(z,u)+f(z,v)+f(z,w) and the multi-variable quadratic functional equation g(x+y+z)+g(x-y+z)+g(x+y-z)+g(-x+y+z)=4g(x)+4g(y)+4g(z). Furthermore, we find out the general solution of the above two functional equations.