• The Journal of Information Technology
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• v.2 no.1
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• pp.53-64
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• 1999

Due to the trend that the wave of the information society is rapidly expanding on a global basis, the level of informatization is emerging as one of the important elements for national competitiveness. To take a competitive position for individuals, corporations, or states beyond their survival in the rapidly changing information environment, they should be able to manage and transmit various information with swiftness and security Today, the exchange of electronic documents or data, through PC which were unknown in the past is indispensable to the expansion of electronic commerce(EC) and eventually contributes to promoting the information society. The improvement of productivity and efficiency through the exchange of electronic documents or data has been recognized as a means to enhance the competitiveness of corporations and states. The United States, the European nations, Japan, and the newly industrialized countries such as Singapore and Taiwan, have been contriving the utilization of electronic documents and the expansion of EC on the strategical dimension of each nation. To activate the use of electronic documents, thus, the purpose of this study is to examine the current environment concerning the use of electronic documents, to investigate the related legal barriers, and to propose some suggestions for reforming the legal system.

• Korean Journal of Child Studies
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• v.22 no.4
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• pp.167-188
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• 2001

This study investigated the relationship of daily life activity experiences to violent behaviors and their moderating effects on the relationship between stress and violent behaviors in early adolescence. A sample of 134 second year middle school students carried electronic watches for one week and provided reports on their objective activity situation and subjective states when signalled at random times. Stress was positively correlated with violent behaviors. Daily activity experiences were correlated with violent behaviors and moderated the relationship between stress and violent behaviors. More time spent in socializing and passive leisure, and negative emotional states during schoolwork and active leisure were correlated with higher violent behaviors. Lower motivational states during schoolwork were correlated with higher violent behaviors. Lower cognition of importance and attention states during schoolwork and higher cognition of importance and attention states during active leisure and maintenance activities were correlated with higher violent behaviors. Finally, the moderating effects of negative emotion during active leisure, motivation and attention states during schoolwork on the relationship of stress with violent behaviors were found among girls only.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.455-466
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• 2016

Chemical-kinetic parameters of the equilibrium constants to evaluate the reverse rate coefficients in the shock layer of a blunt body and the expanding flows are derived for the temperature range from 300 K to 20,000 K. The expanded equilibrium constants for the chemical reactions of the dissociation, ionization, associative ionization, and neutral and charge exchange reactions of the atmospheric species and carbon materials are proposed in the present work. In evaluating the equilibrium constants, the inter-nuclear potential energies of the molecular species are calculated by the analytical potential function of the Hulburt-Hirschfelder model, and the parameters of the analytical model are determined from the semi-classically calculated RKR potentials. The electronic states and energies of the atoms are calculated by the electronic energy grouping model, and the rovibrational states and energies of each electronic states of the molecules are evaluated by the WKB method. The expanded equilibrium constants for 31 types of the reactions are provided for the best curve-fit functions, and the recombination reaction rate coefficients evaluated from the present equilibrium constants are compared with existing measured values.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.169-169
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• 2014

Interfacial electronic structure of bathocuproine and Al was investigated using in-situ photoemission spectroscopy and density functional theory (DFT) calculations. Bathocuproine is used for exciton blocking and electron transport material in organic photovoltaics and Al is typical cathode material. When thin thickness of Al was thermally evaporated on BCP, gap states were observed by ultraviolet photoemission spectroscopy. The closest gap state yielded below 0.3 eV from Fermi level. By x-ray photoemission spectroscopy, interaction of Al with nitrogen of BCP was observed. To understand the origin of gap states, DFT calculation was carried out and gap states was verified with successive calculation of interaction of Al and nitrogen of BCP. Furthermore, emergency of another state above Fermi level was observed. Remarkable reduction of electron injection barrier between Al and BCP, therefore, is possible.

• Korean Journal of Metals and Materials
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• v.46 no.9
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• pp.604-608
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• 2008

The layered compounds vanadium disulfide($VS_2$) and vanadium dioxide($VO_2$) intercalated with Li are investigated for using the Discrete Variational $(DV)-X{\alpha}$ molecular orbital method. The chemical bonding properties of the atoms were examined by bond overlap population of electronic states. The plot of density of states supports the covalent bonding properties by showing the overlap between the atoms. There is a strong tendency of covalent bonding between V-S and V-O. The intensity of covalent bonding of $VS_2$ is stronger than $VO_2$. The net charge of $LiVO_2$ is higher than that of $LiVS_2$. This results of the calculation of $VO_2$ and $VS_2$ indicate that $(DV)-X{\alpha}$ method can be widely applied in the new practical materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.115-118
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• 2004

The phase transition between amorphous and crystalline states in chalcogenide semiconductor films can controlled by electric pulses or pulsed laser beam; hence some chalcogenide semoconductor films can be applied to electrically write/erase nonvolatile memory devices, where the low conductive amorphous state and the high conductive crystalline stale are assigned to binary states. AST(AsSbTe) used to phase change material by applying electical pulses. Thickness of AST chalcogenide thin film have about 100nm. Electrodes are made of ITO and Al. $T_c$(Crystallization temperature) of AST system is lower than that of the GST(GeSbTe) system, so that the current pulse width of crystallization process can be decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.210-213
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• 2004

The phase transition between amorphous and crystalline states in chalcogenide semiconductor films can controlled by electric pulses or pulsed laser beam; hence some chalcogenide semiconductor films can be applied to electrically write/erase nonvolatile memory devices, where the low conductive amorphous state and the high conductive crystalline state are assigned to binary states. Memory switching in chalcogenides is mostly a thermal process, which involves phase transformation from amorphous to crystalline state. The nonvolatile memory cells are composed of a simple sandwich (metal/chalcogenide/metal). It was formed that the threshold voltage depends on thickness, electrode distance, annealing time and temperature, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.365-365
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• 2010

In this paper, silicon nitride thin films with different silane and ammonia gas ratios were deposited and characterized for the antireflection and passivation layer of high efficiency single crystalline silicon solar cells. As the flow rate of the ammonia gas increased, the refractive index decreased and the band gap increased. Consequently, the transmittance increased due to the higher band gap and the decrease of the defect states which existed for the 1.68 and 1.80 eV in the SiNx films. The reduction in the carrier lifetime of the SiNx films deposited by using a higher $NH_3/SiH_4$ flow ratio was caused by the increase of the interface traps and the defect states in/on the interface between the SiNx and the silicon wafer. The silicon and nitrogen rich films are not suitable for generating both higher carrier lifetimes and transmittance. These results indicate that the band gap and the defect states of the SiNx films should be carefully controlled in order to obtain the maximum efficiency for c-Si solar cells.

• Journal of Magnetics
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• v.20 no.4
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• pp.331-335
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• 2015

The ferromagnetic and electronic structure for the $Al_xGa_{1-x}P$ and Mn-doped $AlGaP_2$ was studied by using the self-consistent full-potential linear muffin-tin orbital method. The lattice parameters of un-doped $Al_xGa_{1-x}P$ (x = 0.25, 0.5, and 0.75) were optimized. The band-structure and the density of states of Mn-doped $AlGaP_2$ with or without the vacancy were investigated in detail. The P-3p states at the Fermi level dominate rather than the other states. Thus a strong interaction between the Mn-3d and P-3p states is formed. The ferromagnetic ordering of dopant Mn with high magnetic moment is induced due to the (Mn-3d)-(P-3p)-(Mn-3d) hybridization, which is attributed by the partially filled P-3p bands. The holes are mediated with keeping their 3d-characters, therefore the ferromagnetic state is stabilized by this double-exchange mechanism.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.1
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• pp.27-32
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• 2006

Verbal communication is the most commonly used mean of communication. A spoken word carries a lot of informations about speakers and their emotional states. In this paper we designed a model to recognize emotional states in a speech, a first phase of two phases in developing a toy machine that recognizes emotional states in a speech. We conducted an experiment to extract and analyse the emotional state of a speaker in relation with speech. To analyse the signal output we referred to three characteristics of sound as vector inputs and they are the followings: frequency, intensity, and period of tones. Also we made use of eight basic emotional parameters: surprise, anger, sadness, expectancy, acceptance, joy, hate, and fear which were portrayed by five selected students. In order to facilitate the differentiation of each spectrum features, we used the wavelet transform analysis. We applied ANFIS (Adaptive Neuro Fuzzy Inference System) in designing an emotion recognition model from a speech. In our findings, inference error was about 10%. The result of our experiment reveals that about 85% of the model applied is effective and reliable.