• 제목/요약/키워드: University spin-off

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DESIGN EVALUATION OF NO SPIN DIFFERENTIAL MODELS USING THE AXIOMATIC APPROACH

  • Pyun, Y.S.;Jang, Y.D.;Cho, I.H.;Park, J.H.;Combs, A.;Lee, Y.C.
    • International Journal of Automotive Technology
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    • 제7권5호
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    • pp.595-601
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    • 2006
  • Two No Spin Differential(NSD) models were benchmarked for a project of Dual-Use Technology. The Axiomatic approach is utilized to evaluate the designs of the models. The Independence Axiom is satisfied at the top level of design but not at the second level, which implies the design exhibits coupling and will admit design improvements. The detailed process of design evaluation is described. It is shown that it is possible to develop a unique and evolutionary NSD design by solving the problems that cause coupling within two models.

금속나노입자-유전체 이층 구조 구현을 위한 반투명 Cu 나노입자층 형성에 관한 연구 (Study on Formation of Semitransparent Cu Nanoparticle Layers for Realizing Metal Nanoparticle-Dielectric Bilayer Structures)

  • 윤혜련;조윤이;윤회진;이승윤
    • 한국전기전자재료학회논문지
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    • 제33권6호
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    • pp.460-464
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    • 2020
  • This study reports the fabrication and application of semitransparent Cu nanoparticle layers. Spin coating and subsequent drying of a Cu colloid solution were performed to deposit Cu nanoparticle layers onto Si and glass substrates. As the spin speed of the spin coating increases, the density of the nanoparticles on the substrate decreases, and the agglomeration of nanoparticles is suppressed. This microstructural variation affects the optical properties of the nanoparticle layers. The transmittance and reflectance of the Cu nanoparticle layers increase with increasing spin speed, which results from the trade-off between the exposed substrate area and surface coverage of the Cu nanoparticles. Since the glass substrates coated with Cu nanoparticle layers are semitransparent and colored, it is anticipated that the application of a Cu nanoparticle-dielectric bilayer structure to transparent solar cells will improve the cell efficiency as well as aesthetic appearance.

Three-fold Symmetry Effect on Mn2+ Centers in a LiNbO3 Crystal

  • Park, II-Woo
    • 한국자기공명학회논문지
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    • 제12권2호
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    • pp.103-110
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    • 2008
  • Spin Hamiltonian for the paramagnetic center with a three-fold symmetry and high spin ($S{\geq}2$) multiplicity should contain the fourth order zero-field splitting (ZFS) terms. Electron magnetic resonance transition lines of the center with S = 5/2 are expected to split in a pair when the magnetic field is applied off the principal axes of ZFS, while they are superimposed when the magnetic field is applied parallel to the principal axes of ZFS. In this study we report that the transition lines of $Mn^{2+}$ centers at the three-fold symmetric sites in $LiNbO_3$, chemically equivalent but physically different, split in two due to the nonzero fourth order ZFS term.

Detection and Manipulation of Spin state of Single Molecule Magnet: Kondo resonance and ESR-STM

  • Komeda, T.;Isshiki, H.;Zhang, Y.F.;Katoh, K.;Yoshida, Y.;Yamashita, M.;Miyasaka, H.;Breedlove, B.K.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.16-17
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    • 2010
  • Molecular spintronics has attracted attentions, which combines molecular electronics with the spin degree of freedom in electron transport. Among various molecules as candidates of the molecular spintronics, single molecule magnet (SMM) is one of the most promising material. SMM molecules show a ferromagnetic behavior even as a single molecule and hold the spin information even after the magnetic field is turned off. Here in this report, we show the spin behavior of SMM molecules adsorbed on the Au surface by combining the observation of Kondo peak in the STS and ESR-STM measurement. Kondo resonance state is formed near the Fermi level when degenerated spin state interacts with conduction electrons. ESR-STM detects the Larmor frequency of the spin in the presence of a magnet field. The sample include $MPc_2$ and $M_2Pc_3$ molecules ($M\;=\;Tb^{3+}$, $Dy^{3+}$, and $Y^{3+}$ Pc=phthalocyanine) whose critical temperature as a ferromagnet reaches 40 K. A clear Kondo peak was observed which is originated from an unpaired electron in the ligand of the molecule, which is the first demonstration of the Kondo peak originated from electron observed in the STS measurement. We also observed corresponding peaks in ESR-STM spectra. [1] In addition we found that the Kondo peak intensity shows a clear variation with the conformational change of the molecule; namely the azimuthal rotational angle of the Pc planes. This indicates that the Kondo resonance is correlated with the molecule electronic state. We examined this phenomena by using STM manipulation technique, where pulse bias application can rotate the relative azimuthal angle of the Pc planes. The result indicates that an application of ~1V pulse to the bias voltage can rotate the Pc plane and the Kondo peaks shows a clear variation in intensity by the molecule's conformational change.

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QUANTUM MARKOVIAN SEMIGROUPS ON QUANTUM SPIN SYSTEMS: GLAUBER DYNAMICS

  • Choi, Veni;Ko, Chul-Ki;Park, Yong-Moon
    • 대한수학회지
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    • 제45권4호
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    • pp.1075-1087
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    • 2008
  • We study a class of KMS-symmetric quantum Markovian semigroups on a quantum spin system ($\mathcal{A},{\tau},{\omega}$), where $\mathcal{A}$ is a quasi-local algebra, $\tau$ is a strongly continuous one parameter group of *-automorphisms of $\mathcal{A}$ and $\omega$ is a Gibbs state on $\mathcal{A}$. The semigroups can be considered as the extension of semi groups on the nontrivial abelian subalgebra. Let $\mathcal{H}$ be a Hilbert space corresponding to the GNS representation con structed from $\omega$. Using the general construction method of Dirichlet form developed in [8], we construct the symmetric Markovian semigroup $\{T_t\}{_t_\geq_0}$ on $\mathcal{H}$. The semigroup $\{T_t\}{_t_\geq_0}$ acts separately on two subspaces $\mathcal{H}_d$ and $\mathcal{H}_{od}$ of $\mathcal{H}$, where $\mathcal{H}_d$ is the diagonal subspace and $\mathcal{H}_{od}$ is the off-diagonal subspace, $\mathcal{H}=\mathcal{H}_d\;{\bigoplus}\;\mathcal{H}_{od}$. The restriction of the semigroup $\{T_t\}{_t_\geq_0}$ on $\mathcal{H}_d$ is Glauber dynamics, and for any ${\eta}{\in}\mathcal{H}_{od}$, $T_t{\eta}$, decays to zero exponentially fast as t approaches to the infinity.

EVOLUTIONARY DESIGN OF NO SPIN DIFFERENTIAL MODELS FOR OFF-ROAD VEHICLES USING THE AXIOMATIC APPROACH

  • Pyun, Y.S;Jang, Y.D.;Cho, I.H.;Park, J.H.;Combs, A.;Lee, Y.C.
    • International Journal of Automotive Technology
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    • 제7권7호
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    • pp.795-801
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    • 2006
  • A No Spin Differential (NSD) design has been improved from evaluation of two NSD models utilizing the axiomatic approach. New design parameters of the second level are developed to satisfy the independence axiom. The design matrices are determined to decouple the relationship between design parameters and process parameters. The values of process parameters are then determined to optimize and improve the NSD design. Consequently a unique and evolutionary NSD design is achieved with the aid of the axiomatic approach.

Study on the Isomeric Ratio by Thermal Neutron Activation

  • Bak, Hae-Ill
    • Nuclear Engineering and Technology
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    • 제6권2호
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    • pp.89-96
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    • 1974
  • 열중성자 포획 과정을 통한 핵이성체 쌍 즉 $^{80}$ B $r^{m, g}$, sup 81/S $e^{m, g}$, $^{104}$ R $h^{m, g}$, $^{116}$ I $n^{m, g}$$^{134}$ C $s^{m, g}$ 의 단면적 비를 다루었다. 방사화 방법에 의하여 구하여진 이들 핵이성체 쌍의 단면적 비의 실험측정치를 수정 보완된 Huizenga-Vandenbosch법에 의한 계산치와 비교 검토하였다. 상기 측정치와 계산치는 spin cut-off parameter와 ${\gamma}$-선의 중복도를 적절히 조정함으로써 30% 이내의 오차 범위내에서 일치시킬 수 있었다.

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Novel Patterning of Gold Using Spin-Coatable Gold Electron-Beam Resist

  • Kim, Ki-Chul;Lee, Im-Bok;Kang, Dae-Joon;Maeng, Sung-Lyul
    • ETRI Journal
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    • 제29권6호
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    • pp.814-816
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    • 2007
  • Conventional lithography methods of gold patterning are based on deposition and lift-off or deposition and etching. In this letter, we demonstrate a novel method of gold patterning using spin-coatable gold electron-beam resist which is functionalized gold nanocrystals with amine ligands. Amine-stabilized gold electron beam resist exhibits good sensitivity, 3.0 mC/$cm^2$, compared to that of thiol-stabilized gold electron beam resists. The proposed method reduces the number of processing steps and provides greater freedom in the patterning of complex nanostructures.

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QUASILINEAR SCHRÖDINGER EQUATIONS FOR THE HEISENBERG FERROMAGNETIC SPIN CHAIN

  • Yongkuan Cheng;Yaotian Shen
    • 대한수학회보
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    • 제61권2호
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    • pp.541-556
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    • 2024
  • In this paper, we consider a model problem arising from a classical planar Heisenberg ferromagnetic spin chain $-{\Delta}u+V(x)u-{\frac{u}{\sqrt{1-u^2}}}{\Delta}{\sqrt{1-u^2}}={\lambda}{\mid}u{\mid}^{p-2}u$, x ∈ ℝN, where 2 ≤ p < 2*, N ≥ 3. By the Ekeland variational principle, the cut off technique, the change of variables and the L estimate, we study the existence of positive solutions. Here, we construct the L estimate of the solution in an entirely different way. Particularly, all the constants in the expression of this estimate are so well known.

Flexible OTFT-OLED Display Panel using Ag-paste for Source and Drain Electrodes

  • Ryu, Gi-Seong;Kim, Young-Bea;Song, Hyun-Jin;Song, Chung-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1789-1791
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    • 2007
  • We fabricated OTFT-OLED display panel by using Ag-paste for source and drains electrode of OTFTs. The OTFTs were fabricated by solution processes such as spin-coating for PVP gate dielectric and screen printing for S/D electrodes with Ag-paste, except pentacene active layer which was deposited by evaporation. The mobility was 0.024 cm2/V.sec , off state current ${\sim}10-11A$, threshold voltage 7.6 V and on/off current ratio ${\sim}105$. The panel consisted of 16 x 16 pixels and each pixel consisted of 2 OTFTs, 1 Capacitor and 1 OLED. The pixels successfully worked in terms of current magnitude supplied to OLED and the control ability of driving and switching OTFTs.

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