• Bulletin of the Korean Mathematical Society
• /
• v.52 no.1
• /
• pp.159-172
• /
• 2015

This paper presents a new sufficient condition for the oscillation of all solutions of difference equations with several deviating arguments and oscillating coefficients. Corresponding difference equations of both retarded and advanced type are studied. Examples illustrating the results are also given.

• Bulletin of the Korean Mathematical Society
• /
• v.55 no.4
• /
• pp.1161-1178
• /
• 2018

In this paper, we consider the Cauchy problem for a class of nonlinear sixth-order wave equation. The global existence and the finite time blow-up for the problem are proved by the potential well method at both low and critical initial energy levels. Furthermore, we present some sufficient conditions on initial data such that the weak solution exists globally at supercritical initial energy level by introducing a new stable set.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.12
• /
• pp.3825-3828
• /
• 2013

In this study, the influences of aniline to acid composition were investigated on the electrical conductivity of PANI-PAAMPSA. The ratio of aniline to sulfonic acid groups was optimized for the maximum conductivity of PANI-PAAMPSA. The conductivity is strongly correlated with the electronic structure of PANI-PAAMPSA; the highest conductivity of PANI-PAAMPSA was observed when PANI has the longest conjugation length.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.12
• /
• pp.4227-4232
• /
• 2011

A number of new 2,5-disubstituted 1,3,4-thiadiazole and their S- or N-substituted derivatives as well as the corresponding sugar hydrazone derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). The synthesized compounds displayed different degrees of antimicrobial activities or inhibitory actions.

• Bulletin of the Korean Space Science Society
• /
• 2001.04a
• /
• pp.49-49
• /
• 2001

• Proceedings of the Korea Contents Association Conference
• /
• 2012.05a
• /
• pp.9-10
• /
• 2012

스마트단말기기의 확산에 따라 다양한 서비스 산업이 발전하듯이 이제 교육기관에서도 이러한 환경적 변화에 발맞추어 학생들의 자유로운 사고와 활동을 기록하고 저장할 수 있는 환경을 구축하고 있다. 이러한 환경적 변화에 대응하고 기존 역할을 함께 수행할 수 있는 교육용 스마트 전자게시판을 설계하고자 한다.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1667-1670
• /
• 2009

• Bulletin of the Korean Chemical Society
• /
• v.29 no.9
• /
• pp.1807-1810
• /
• 2008

• Bulletin of the Korean Chemical Society
• /
• v.33 no.6
• /
• pp.2063-2066
• /
• 2012

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.609-614
• /
• 2013

Extended H$\ddot{u}$ckel tight-binding band structure calculations are used to address the chemical bonding and elastic properties of $Zr_2AC$ (A=Al, Si, P, and S). Elastic properties are interpreted by analyzing the density of states and the crystal orbital overlap population for the respective phases. Our results show that the bulk modulus of these ternary compounds is determined by the strength of Zr-A bonds.