• Title/Summary/Keyword: valence state

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Valence State of the Sm Metal

  • Jang, Y.R.;Min, Byung-Il
    • Journal of Magnetics
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    • v.3 no.1
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    • pp.1-3
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    • 1998
  • Valence state of the Sm metal is investigated using the total energy linearized muffin-tin orbital (LMTO) band method for the observed Sm-type crystal structure. We have considered both the relativistic and the semi-relativistic description of 4f-core electrons. We have found that, in the paramagnetic phase of bulk Sm, the trivalent valence state is more stable at the observed lattice constant than the divalent valence state.

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Effective Hamiltonian Study on the Valence States of NH and $NH^+$

  • Jong Keun Park;Hosung Sun
    • Bulletin of the Korean Chemical Society
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    • v.11 no.1
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    • pp.34-41
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    • 1990
  • The second order ab initio effective valence shell Hamiltonian is calculated for the valence state potential energy curves of NH and $NH^+$. From the potential energy curves various spectroscopic constants of valence states are determined. The results are in good agreement with experiments and configuration interaction calculations. They show the composite picture of potential energy curves and also indicate that the second order effective Hamiltonian theory is adequate for describing various valence states of a molecule and its ions simultaneously.

Dipole Moments of the OH, OH$^+$, and OH$^-$Valence States by ab initio Effective Valence Shell Hamiltonian Method

  • Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
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    • v.9 no.2
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    • pp.101-105
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    • 1988
  • The ab initio effective valence shell Hamiltonian method, based on quasidegenerate many-body perturbation theory, is generalized to calculate molecular properties as well as the valence state energies which have previously been determined for atoms and small molecules. The procedure requires the evaluation of effective operator for each molecular property. Effective operators are perturbatively expanded in powers of correlation and contain contributions from excitations outside of the multireference valence space. To demonstrate the validity of this method, calculations for dipole moments of several low lying valence states of OH, $OH^+$, and $OH^-$ to first order in the correlations have been performed and compared with configuration interaction calculations.

3, 4, 5 Year-old Children's Beliefs about Trait Stability Based on Trait Type and Valence (3, 4, 5세 유아의 특질 유형과 정서가에 따른 특질 안정성에 대한 믿음)

  • Lee, Jeong-Hyeon;Yi, Soon-Hyung
    • Korean Journal of Human Ecology
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    • v.21 no.1
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    • pp.83-93
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    • 2012
  • This study examined young children's beliefs about trait stability based on trait type and valence. Participants included 120 children (40 three-year-olds, 40 four-year-olds, and 40 five-year olds) recruited from 3 day-care-centers and 1 kindergarten in Seoul and Kyung-Ki province. Results revealed that young children's understanding of traits differed based on trait type and valence. Children demonstrated a strong belief that social-intention traits are more stable and harder to change when compared to internal-state traits. Young children's beliefs on trait stability were also strongly influenced by trait valence. They believed that negative traits are more likely to change for the better while positive traits have greater stability and are less likely to change over time.

Ab initio Effective Hamiltonian Calculations on the Valence States of SiH, $SiH^+$, PH and $PH^+$

  • Park Jong Keun;Sun Hosung
    • Bulletin of the Korean Chemical Society
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    • v.13 no.4
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    • pp.429-440
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    • 1992
  • The second order ab initio effective valence shall Hamiltonian ($H^v$) which is based on quasidegenerate many-body perturbation theory is applied to the SiH, PH, and their positive ions. A singie Hv computation for the neutral molecule is used for a whole set of valence states of a molecule and its ion simultaneously. The low-lying valence state potential energy curves of SiH, PH and their positive ions are computed. And various spectroscopic constants of the low-lying bound valence states are determined from the potential energy curves. The $H^v$ results are found to be in good agreement with other theoretical and experimental data.

Intermediate Valence State of Cerium in Intermetallics

  • Suski, Wojciech
    • Journal of Magnetics
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    • v.4 no.3
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    • pp.102-106
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    • 1999
  • Ce exhibits the intermediate valence (IV) state both as an element and in its compounds. In the present review characteristic behavior of the materials showing the IV state are described. Then the methods of producing this state : the application of the external pressure, temperature and magnetic field as well as the alloying are being discussed. An identification of the IV state is frequently not a simple goal and the best results can be obtained using a combination of various independent methods. Particular attention is paid to the X-ray spectroscopy, lattice parameters and the magnetic properties. As the examples of the IV state in the Ce compounds the properties of following materials are reported : CeRhSb, $CeCu_5In_7, CeAg_6In_6, Sc_{1-x}Ce_xFe_4Al_8 $and for comparison Sc1-xYbxFe4Al8.

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Valence Band Photoemission Study of the Kondo Insulator CeNiSn

  • Kang, J.S.;Olson, C.G.;Ouki, Y.
    • Journal of Magnetics
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    • v.2 no.4
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    • pp.111-115
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    • 1997
  • The electronic structure of the Kondo insulator CeNiSn has been investigated by using photoemission spectroscopy. A satellite feature is observed in the valence band spectrum about 6 eV below the Ni 3d main peak, indicating a strong Ni 3d Coulomb correlation in CeNiSn. The Ce 4f partial spectral weight exhibits three peak structures, including one due to the 4f1\longrightarrow4f0 transition, another near EF, and the other which overlaps the Ni 3d main peak. We interpret the peak near EF as reflecting mainly the Ce 4f/Sn 5p hybridization, whereas that around the ni 3d main peak as reflecting both the Ce 4f/Ni 3d and Ce 5d/Ni 3d hybridization. Yield measurements across the 4d\longrightarrow4f threshold indicate the Ce valence to be close to 3+. The prominent Fermi edge suggests a metallic ground state in CeNiSn.

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Photoelectron Spectroscopy Studies of the Electronic Structures of Al/RbF and $Al/CaF_2$ Cathodes for $Alq_3$-based Organic Light-emitting Devices

  • Park, Yong-Sup;Lee, Jou-Hahn
    • Journal of Information Display
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    • v.6 no.1
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    • pp.28-32
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    • 2005
  • The electronic structures of Al/RbF/tris-(8-hydroxyquinoline)aluminium ($Alq_3$) and $Al/CaF_2/Alq_3$interfaces were investigated using x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). For both systems, the UPS showed a significant valence band shift following the deposition of the thin fluoride layers on $Alq_3$. However, the formation of gap state in valence region and the extra peak N 1s core level spectra showed different trends, suggesting that the alkali fluoride and alkali-earth fluoride interlayer have different reaction mechanisms at the interface between Al cathode and $Alq_3$. In addition, the deposition of Al has considerably less effect on the valence band shift compared to the deposition of both RbF and $CaF_2$. These results suggest that the charge transfer across the interface and the resulting gap state formation may have lesser effect on the enhancement of organic light-emitting device performance than the observed valence band shift, which is thought to lower the electron injection barrier.

Photocurrent Study on the Splitting of the Valence Band and Growth of $CdIn_2Te_4$ Single Crystal by Bridgman method (Bridgman법에 의해 성장된 $CdIn_2Te_4$ 단결정의 가전자 갈라짐에 대한 광전류 연구)

  • Baek, Seung-Nam;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.347-351
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    • 2003
  • A p-$CdIn_2Te_4$ single crystal has been grown by the Bridgman method without a seed crystal in a tree-stage vertical electric furnace. From photocurrent measurements, it was found that three peaks, A, B, and C, corresponded to an intrinsic transition due to the band-to-band transition from the valence band states ${\Gamma}_7(A),\;{\Gamma}_6(B),\;and\;{\Gamma}_7(C)$ to the conduction band state ${\Gamma}_6$, respectively. Also, the valence band splitting of the $CdIn_2Te_4$ crystal has been confirmed by photocurrent spectroscopy. The crystal field splitting and the spin orbit splitting were obtained to be 0.2360 and 0.1119 eV, respectively. Also, the temperature dependence of the band gap energy of the $CdIn_2Te_4$ crystal has been driven as the following equation of $E_g(T)\;=E_g(0)\;-\;(9.43\;{\times}\;10^{-3})T^2/(2676\;+\;T)$. In this equation, the Eg(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band state A, B, and C, respectively. The band gap energy of the p-$CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

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Arousal and Valence Classification Model Based on Long Short-Term Memory and DEAP Data for Mental Healthcare Management

  • Choi, Eun Jeong;Kim, Dong Keun
    • Healthcare Informatics Research
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    • v.24 no.4
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    • pp.309-316
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    • 2018
  • Objectives: Both the valence and arousal components of affect are important considerations when managing mental healthcare because they are associated with affective and physiological responses. Research on arousal and valence analysis, which uses images, texts, and physiological signals that employ deep learning, is actively underway; research investigating how to improve the recognition rate is needed. The goal of this research was to design a deep learning framework and model to classify arousal and valence, indicating positive and negative degrees of emotion as high or low. Methods: The proposed arousal and valence classification model to analyze the affective state was tested using data from 40 channels provided by a dataset for emotion analysis using electrocardiography (EEG), physiological, and video signals (the DEAP dataset). Experiments were based on 10 selected featured central and peripheral nervous system data points, using long short-term memory (LSTM) as a deep learning method. Results: The arousal and valence were classified and visualized on a two-dimensional coordinate plane. Profiles were designed depending on the number of hidden layers, nodes, and hyperparameters according to the error rate. The experimental results show an arousal and valence classification model accuracy of 74.65 and 78%, respectively. The proposed model performed better than previous other models. Conclusions: The proposed model appears to be effective in analyzing arousal and valence; specifically, it is expected that affective analysis using physiological signals based on LSTM will be possible without manual feature extraction. In a future study, the classification model will be adopted in mental healthcare management systems.