• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.457-460
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• 1989

This note considers the problems of finding a pole assignment controller for a plant with parameter perturbations. Based on Kharitonov's theorem and its generalized results, we propose a design method of controller using linear transformations such that it guarantees the desired damping ratio.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.267-268
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• 2012

본 논문에서는 효과적인 영상암호를 위하여 영상을 여러 단계별 블록화 한 뒤 암호화 과정을 수행한다. 이러한 암호화 과정의 효과적인 연산을 위하여 기본 행렬 변환을 이용한 대수적 연산과 비정칙적 복잡 함수의 무작위적 특이성을 이용한다.

• Communications of the Korean Mathematical Society
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• v.24 no.4
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• pp.501-508
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• 2009

This paper presents a new representation algorithm which computes the representation for elements of a free group generated by two linear fractional transformations and also the justification of the algorithm in order to show how it operates correctly and efficiently according to inputs.

• Bulletin of the Korean Chemical Society
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• v.10 no.2
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• pp.129-132
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• 1989

Reactions of thebaine with phenylsulfonylpropadiene in various solvents were investigated. It was found that Diels-Alder reaction adduct was obtained in nonpolar solvent, while addition reaction adduct was obtained in polar solvent. Transformations of these two products were also carried out.

• Bulletin of the Korean Chemical Society
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• v.16 no.10
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• pp.985-988
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• 1995

2-Epideoxymannojirimycin 1 and (2R,3R,4R,5R)-3,4,5-trihydroxypipecolic acid 2 were prepared starting from D-glucosamic acid as a chiral educt. Key transformations were selective removal of the terminal isopropylidene group and intramolecular cyclization by SN2 reaction.

• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1369-1372
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• 1998

The (-)-polyoxamic acid 2 and its stereoisomer 3 have been prepared from D-glucono-δ-lactone which has three available stereocenters as required for 2 and 3. Key transformations included the selective cleavage of the terminal isopropylidene group.

• Journal of applied mathematics & informatics
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• v.40 no.1_2
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• pp.283-288
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• 2022

In this paper we characterize the sets of summability factors (|C, 0|_k, |R, p_n|_s) and (|R, p_n|_k, |C, 0|_s), 1 < k ≤ s < ∞, which also extends some known results.

• Honam Mathematical Journal
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• v.44 no.1
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• pp.26-35
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• 2022

In this paper we introduce two type of representations of the Pascal matrix via induced transformations of some q-derivatives as well as their some combinatorial applications.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2546-2552
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• 2012

A novel biguanide-functionalized $Fe_3O_4/SiO_2$ magnetite nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperbase in chemical transformations. The structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (TEM), powder X-ray diffraction (XRD), vibrating sample magnetometry (VSM), elemental analyzer (EA), thermogravimetric analysis (TGA), $N_2$ adsorption-desorption (BET and BJH) and FT-IR. The biguanide-functionalized $Fe_3O_4/SiO_2$ nanoparticles showed a superpara-magnetic property with a saturation magnetization value of 46.7 emu/g, indicating great potential for application in magnetically separation technologies. In application point of view, the prepared catalyst was found to act as an efficient recoverable nanocatalyst in nitroaldol and domino Knoevenagel condensation/Michael addition/cyclization reactions in aqueous media under mild condition. Additionally, the catalyst was reused six times without significant degradation in catalytic activity and performance.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.63-64
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• 2013

Induction motors' faults detection is almost a popular topic among researchers. Monitoring the output of motors is a key factor in detecting these faults. (Short-time) Fourier, (continuous, discrete) wavelet, and extended Park vector transformations are among the methods for fault detection. One major deficiency of these methods is not being able to detect the severity of faults that carry low energy information, e.g. in ball bearing system failure, there is absolutely no way to detect the severity of fault using Fourier or wavelet transformations. In this paper, the authors have applied the Discrete Wavelet Transform (DWT) frequency-domain analysis to detect bearing faults in an induction motor. In other words, in discrete transform which the output signal is decomposed in several steps and frequency resolution increases considerably, the frequency-band analysis is performed and it will be verified that first of all, fault sidebands become more recognizable for detection in higher levels of decomposition, and secondly, the inner race bearing faults turn out easier in these levels; and all these matter because of eliminating the not-required high energy components in lower levels of decomposing.