• 한국지능시스템학회논문지
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• 제7권3호
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• pp.12-20
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• 1997

본 논문에서는 동작 특성을 알 수 없는 미지의 프로세스를 제어하는 경우에 있어 제어계의 스텝응답으로부터 제어대상의 특성을 파악하여 제어 방법을 수정하는 학습방법을 제안하였다. 제어기는 이러한 목적에 맞는 퍼지제어기가 선택된다. 본 논문의 주된 목표는 프로세？의 스텝응답으로부터 얻어진 제안된 특성하에서 제어계의 응답을 개선할 수 있는 지식을 얻는 것이다. 이를 위해 많은 제어대항에 대한 시뮬레이션을 수행하였고, 이를 통해 적절한 튜닝 방법을 얻었다. 또한 최적의 샘플링 간격 선정에 대한 연구도 수행하였다.

• Asia pacific journal of information systems
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• 제11권2호
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• pp.159-180
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• 2001

Despite the large and ongoing investments in information systems and technologies, many organizations still suffer from the lack of integration and interoperability of multiple information systems, In order to deal with these enduring problems, a number of government organizations and corporate firms in the United States have developed and maintained IT architectures through enterprise architecture planning. An IT architecture is a decision-making framework for IT planners and developers, establishing guidelines for the individual IT resource owners and users. It provides guidance to those involved in building and maintaining IT systems and infrastructure. Enterprise architecture planning represents a new paradigm of information systems planning in that it addresses the long-term view of the enterprise organization from top-level principles to detailed technology architectures. This paper explores a couple of cases in the successful implementation of IT architectures in both public and private sectors, and proposes a step-by-step methodology for building an effective IT architecture.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.241-245
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• 2004

An analytical study was conducted to characterize the fatigue crack growth behavior of pre-cracked aluminum plates repaired with asymmetric bonded composite patch. For single-sided repairs, due to the asymmetry and the presence of out-of-plane bending, crack front shape would become skewed curvilinear started from a uniform through-crack profile, as observed from previous studies. In this study, the fatigue analysis of single-sided repairs considering crack front shape development was conducted by implementing three-dimensional successive finite element method coupled with linear elastic fracture mechanics (LEFM) concept, which enables the growing crack front to be directly traced and modeled in a step by step way. Through conducting present analysis technique, crack path of the patched plate as well as the fatigue life was evaluated with sufficient accuracy. The analytical predictions of both the crack front shape evolution and the fatigue life were in good agreement with the experimental observations.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.121-127
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• 2013

New types of monocyclic ${\beta}$-lactams constitute an important class of compounds due to their unique structures and natures. Here, the design and synthesis of new 4-alkylthio monocyclic ${\beta}$-lactams 2a and 3a are reported. Significantly, compounds 2a and 3a, while keeping a monocyclic system, were designed to contain all of the substructures provided by the cleavage of C(2)-C(3) bond in penicillins. Efficient synthetic pathways for compounds 2a and 3a were established based on two different strategies. Compound 2a was synthesized from raw materials, using 4-acetoxyazetidin-2-one as a key intermediate, through a ten-step synthetic sequence in 3% overall yield. Compound 3a was synthesized from potassium salt of penicillin G (17), using the degraded product 20 as a key intermediate, through a six-step synthetic sequence in 11% overall yield. 4-Alkylthioazetidin-2-one derivatives, introduced in this study, could serve as valuable intermediates for the development of new monocyclic ${\beta}$-lactams.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1361-1365
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• 2013

The smallest ketenimine and hydrogen cyanide N-methylide ($CH_2CNH$ and $CH_2NCH$) are provided from the argon/acetonitrile matrix samples exposed to radiation from laser ablation of transition-metals. New infrared bands are observed in addition to better determination of the vibrational characteristics for the previously reported bands, and the $^{13}C$ substituted isotopomers ($^{13}{CH_2}^{13}CNH$ and $^{13}CH_2N^{13}CH$) are also generated. Density functional frequency calculations and the D and $^{13}C$ isotopic shifts substantiate the vibrational assignments. $CH_2CNH$ is probably produced through single-step conversion of $CH_3CN$, whereas $CH_2NCH$ through two-step conversion via 2H-azirine. Inter-conversions between these two products evidently do not occur during photolysis and annealing.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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• pp.27-32
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• 1999

A numerical study based on the three-dimensional thin-layer Navier-Stokes solver is carried out to analyze the flowfield through a single stage transonic compressor. Explicit four-step Runge-Kutta scheme with spatially variable time step and implicit residual smoothing is used. The governing equations are discretized with exploit finite difference method. Mixed-out average method is used at the interface between rotor and stator. And, an artificial dissipation model is used to assure the stability of solution. The results with k-$\omega$ turbulence model were compared to the results with Baldwin-Lomax model, and physical phenomena of transonic compressor are presented. The two turbulence models give the results that show reasonably good agreements with experimental data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2358-2361
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• 2001

In recent years there have been increasing interests in real-time object tracking with image information. Since image information is affected by illumination, this paper presents the real-time object tracking method based on neural networks which have robust characteristics under various illuminations. This paper proposes three steps to track the object and the fast tracking method. In the first step the object color is extracted using neural networks. In the second step we detect the object feature information based on invariant moment. Finally the object is tracked through a shape recognition using neural networks. To achieve the fast tracking performance, this paper first has a global search of entire image and tracks the object through local search when the object is recognized.

• 한국통신학회논문지
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• 제27권3A호
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• pp.240-248
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• 2002

본 논문에서는 연속영상에서 움직이는 객체의 motion에 기반하여 영상을 분할하는 새로운 알고리즘을 제안하였다. 전체적인 분할 과정은 2단계로 구성되어진다. 첫 단계는 '픽셀 레이블링' 단계이며, 두 번째 단계는 'motion 분할' 단계이다. '픽셀 레이블링' 단계에서는 optical flow에 의해 발생하는 속도 벡터들의 크기에 따라 영상의 각 픽셀에 레이블을 부여한다. 'Motion 분할' 단계에서는 첫 단계에서 생겨난 불필요한 잡음을 제거하기 위해 motion 필드를 마코프 랜덤 필드로 모델링하여 에너지 최소화를 통해 motion을 분할한다. 실험결과, 제안된 알고리즘이 연속영상에서 움직이는 객체의 motion을 효율적으로 분할함을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.678-681
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• 1991

The Wittig-oxy-Cope rearrangements of deprotonated diallyl ether, I, $CH_2={\bar{C}}H-CH-O-CH_2-CH=CH_2$, have been investigated theoretically by the AM1 method. A two step mechanism forming a Wittig product ion, II, $(CH_2=CH)$ $(CH_2=CH-CH_2)$ $CHO^-$, through a radical-pair intermediate was found to provide the most favored reaction pathway in the Wittig rearrangement. The subsequent oxy-Cope rearrangement from species II also involves a two step mechanism through a biradicaloid intermediate. The intramolecular proton transfer in I (to form $CH_2=CH-CH_2-O-{\bar{C}}H-CH=CH_2$) is a higher activation energy barrier process compared to the Wittig and oxy-Cope rearrangements and is considered to be insignificant. These results are in good agreement with the condensed-phase as well as gas-phase experimental results.

• International Journal of Computer Science & Network Security
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• 제21권4호
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• pp.272-276
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• 2021

Presently, Online / Offline Users are facing cyber attacks every day. These cyber attacks affect user's performance, resources and various daily activities. Due to this critical situation, attention must be given to prevent such users through cyber attacks. The objective of this research paper is to improve the IDS systems by using machine learning approach to develop a hybrid model which controls the cyber attacks. This Hybrid model uses the available KDD 1999 intrusion detection dataset. In first step, Hybrid Model performs feature optimization by reducing the unimportant features of the dataset through decision tree, support vector machine, genetic algorithm, particle swarm optimization and principal component analysis techniques. In second step, Hybrid Model will find out the minimum number of features to point out accurate detection of cyber attacks. This hybrid model was developed by using machine learning algorithms like PSO, GA and ELM, which trained the system with available data to perform the predictions. The Hybrid Model had an accuracy of 99.94%, which states that it may be highly useful to prevent the users from cyber attacks.