• The Journal of the Acoustical Society of Korea
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• v.17 no.4E
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• pp.3-10
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• 1998

This paper concerns the dynamical behavior, in probabilistic sense, of a feedforward neural network performing auto association for novelty. Networks of retinotopic topology having a one-to-one correspondence between and output units can be readily trained using back-propagation algorithm, to perform autoassociative mappings. A novelty filter is obtained by subtracting the network output from the input vector. Then the presentation of a "familiar" pattern tends to evoke a null response ; but any anomalous component is enhanced. Such a behavior exhibits a promising feature for enhancement of weak signals in additive noise. As an analysis of the novelty filtering, this paper shows that the probability density function of the weigh converges to Gaussian when the input time series is statistically characterized by nonsymmetrical probability density functions. After output units are locally linearized, the recursive relation for updating the weight of the neural network is converted into a first-order random differential equation. Based on this equation it is shown that the probability density function of the weight satisfies the Fokker-Planck equation. By solving the Fokker-Planck equation, it is found that the weight is Gaussian distributed with time dependent mean and variance.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.201-204
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• 2002

The rates of the aminolysis of S-phenyl substituted-acetate series $(RC(=O)SC_6H_4Z$, with R=Me, Et, i-Pr, t-Bu and Bn) with benzylamines $(XC_6H_4CH_2NH_2)$ are not correlated simply with the Taft's polar $({\sigma}^{\ast})$ and/or steric effect constants $(E_s)$ of the substituents due to abnormally enhanced rate of the substrate with R=Et. Furthermore, the cross-interaction constant, ${\rho}x_z$ , is the largest with R=Et. These anomalous behaviors can only be explained by invoking the vicinal bond $({\sigma})$-antibond $({\sigma}^{\ast})$ charge transfer interaction between C-$C{\alpha}$ and C-S bonds. In the tetrahedral zwitterionic intermediate, $T^{\pm}$ , formed with R=Et the vicinal ${\sigma}_{c-c}-{\sigma}^{\ast}_{c-s}$ delocalization is the strongest with an optimum antiperiplanar arrangement and a narrow energy gap, ${\Delta}{\varepsilon}={\varepsilon}_{{\sigma}^{\ast}}-{\varepsilon}_{\sigma}$. Due to this charge transfer interaction, the stability of the intermediate increases (with the concomitant increase in the equilibrium constant K (= $k_a/k_{-a}$)) and also the leaving ability of the thiophenolate leaving group increases (and hence $k_b$ increases) so that the overall rate, $k_n\;=\;Kk_b$, is strongly enhanced. Theoretical support is provided by the natural bond orbital (NBO) analyses at the B3LYP/6-31+$G^{\ast}$ level. The anomaly exhibited by R=Et attests to the stepwise reaction mechanism in which the leaving group departure is rate limiting.

• Transactions on Electrical and Electronic Materials
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• v.7 no.3
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• pp.149-153
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• 2006

An attempting to produce a p-type diluted magnetic semiconductor (DMS) using $Ti_{1-x}Co_xO_{2-\delta}-based$ thin films was made by suitable control of the deposition parameters including deposition temperature, deposition pressure, and doping level using a pulsed laser deposition method. T$Ti_{0.97}Co_{0.03}O_{2-\delta}-based$ (TCO) films deposited at $500^{\circ}C$ at a pressure of $5\times10^{-6}$ Torr showed an anomalous Hall effect with p-type characteristics. On the other hand, films deposited at $700^{\circ}C$ at $5\times10^{-6}$ Torr showed n-type behaviors by a decreased solubility of cobalt. The charge carrier concentration in the p-type TCO films was approximately $7.9\times10^{22}/cm^3$ at 300 K and the anomalous Hall effect in the p-type TCO films was controlled by a side-jump scattering mechanism. The magnetoresistance (MR), measured at 5 K in p-type TCO films showed a positive behavior in an applied magnetic field and the MR ratio was approximately 3.5 %. The successful preparation of p-type DMS using the TCO films has the potential for use in magnetic tunneling junction devices.

• Journal of Magnetics
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• v.10 no.3
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• pp.95-98
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• 2005

We report hole-induced ferromagnetism in diluted magnetic semiconductor $Zn_{0.99}Mn_{0.01}$ films grown on $SiO_2/Si$ substrates by reactive sputtering. The p-type conduction with hole concentration over $10^{18}\;cm^{-3}$ is achieved by P doping followed by rapid thermal annealing at $800^{\circ}C$ in a $N_2$ atmosphere. The p-type $Zn_{0.99}Mn_{0.01}O:P$ is carefully examined by x-ray diffraction and transmission electron microscopy. The magnetic measurements for $p-Zn_{0.99}Mn_{0.01}O:P$ clearly reveal ferromagnetic characteristics with a Curie temperature above room temperature, whereas those for $n-Zn_{0.99}Mn_{0.01}O:P$ show paramagnetic behavior. The anomalous Hall effect at room temperature is observed for the p-type film. This result strongly supports hole-induced room temperature ferromagnetism in $p-Zn_{0.99}Mn_{0.01}O:P$.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.143.1-143.1
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• 2007

• Journal of Information Display
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• v.13 no.1
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• pp.31-36
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• 2012

Ferroelectric liquid crystal parameters, spontaneous polarization, and transition temperature were studied as a function of cell thickness. These parameters were found to increase with increasing cell thickness, but an exception was observed for the transition temperature in the case of a thin cell. A simple Landau model is presented to interpret the theoretical and experimental observations. The anomalous behavior is attributed to the electroclinic effect and is explained using the Landau model.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.269-272
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• 2001

본 논문에서는 베이지안 네트워크와 통합 감사자료를 이용하여 시스템 사용자에 대한 비정상행위를 탐지하고 분석하는데 효과적인 모델을 제안하고자 한다. 이를 위해 리눅스 시스템에서의 여러 가지 감사자료들을 통합한 감사자료로부터 사용자의 행위에 대해 베이지안 네트워크로 구성하고자 한다. 베이지안 네트워크를 구성할 때 효율적인 학습이 가능한 Sparse Candidate 알고리즘을 적용하고, 감사자료의 일부가 결여되어 있는 경우에도 추론이 가능하도록 MCMC(Markov Chain Monte Carlo)의 일종인 Gibbs Sampling 방법을 적용한다.

• Bulletin of the Korean Chemical Society
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• v.1 no.1
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• pp.1-4
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• 1980

During the study of the kinetics of Cl atom reactions by atomic fluorescence method we observed anomalous fluorescence emission for some atomic transitions. Instead of usual decrease of the fluorescence intensity by adding substrate, 1363 A transition $(^2P^{\circ}_{3/2}{\to}^2P_{1/2})$ intensity increased by adding substrate. From the normally behaved fluorescence lines the absolute rate constant for the reaction, Cl + $CH_3Cl{\to}$, was found to be $4.2{\times}10^{-13}$ cc/molecule sec at $20^{\circ}C$.

• Convergence Security Journal
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• v.12 no.4
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• pp.77-84
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• 2012

The control network has been operated in a closed. But it changes to open to external for business convenience and cooperation with several organizations. As the way of connecting with user extends, the risk of control network gets high. Thus, in this paper, proposed the technique of an anomalous event detection using white-list for control network security and minimizing the cyber threats. The proposed method can be collected and cataloged of only normal data from traffic of internal network, control network and field devices. Through way to check the this situation, we can separate normal and abnormal behavior.

• Journal of Magnetics
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• v.1 no.1
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• pp.24-30
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• 1996

The relationship between effective permeability and the remanence ratio of an Fe-based amorphous alloy (Metglas 2605S3A) is investigated over a wide frequency range, in an effort to understand magnetization behavior of the alloy. In the frequency range from 1 to 200 kHz, the permeability is maximum at the remanence ratio of 0.4-0.5 and, at frequencies over 500 kHz, the correlation with negative coefficients emerges indicating that the permeability decreases with the remanent ratio, except for the ribbon coated with an insulating layer of MgO which exhibits both high values of the effective permeability and remanence ratio. It is considered from the correlation results that the boundary at which the dominant magnetization mechanism changes from domain wall motion to spin rotation is near 500 kHz. The core loss is also investigated as a function of annealing time when the samples are annealed at a fixed temperature of $435^{\circ}C$. The core loss in most cases decreases with the annealing time, the degree of the loss may consist of the hysteresis loss and anomalous eddy current loss. The two loss components are considered to be of similar magnitudes at low frequencies while, at high frequencies, the dominant contribution to the total loss is the anomalous loss.