• Title/Summary/Keyword: MO calculation

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Analysis of Off-axis Integral Floating System Using Concave Mirror

  • Kim, Young Min;Jung, Kwang-Mo;Min, Sung-Wook
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.270-276
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    • 2012
  • An off-axis integral floating system using a concave mirror is analyzed to resolve the image distortion incurred by the off-axis optical arrangement. The concave mirror can be adopted as the floating device to improve the optical efficiency. The image distortion due to the tilting axis of the concave mirror needs to be analyzed precisely to generate the pre-distortion image. In this paper, we calculate the image deformation in the off-axis structure of the concave mirror using the geometrical optics. Using the calculation results, the compensated elemental image can be generated for the pre-distortion integrated image, which can be projected to the floating 3D image without image distortion. The basic experiments of the off-axis integral floating are presented to prove and verify the proposal.

A CLB-based CPLD Low-power Technology Mapping Algorithm considered a Trade-off

  • Youn, Choong-Mo;Kim, Jae-Jin
    • Journal of information and communication convergence engineering
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    • v.5 no.1
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    • pp.59-63
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    • 2007
  • In this paper, a CLB-based CPLD low-power technology mapping algorithm considered a Trade-off is proposed. To perform low-power technology mapping for CPLDs, a given Boolean network has to be represented in a DAG. The proposed algorithm consists of three steps. In the first step, TD(Transition Density) calculation has to be performed. Total power consumption is obtained by calculating the switching activity of each node in a DAG. In the second step, the feasible clusters are generated by considering the following conditions: the number of inputs and outputs, the number of OR terms for CLB within a CPLD. The common node cluster merging method, the node separation method, and the node duplication method are used to produce the feasible clusters. In the final step, low-power technology mapping based on the CLBs packs the feasible clusters. The proposed algorithm is examined using SIS benchmarks. When the number of OR terms is five, the experiment results show that power consumption is reduced by 30.73% compared with TEMPLA, and by 17.11 % compared with PLA mapping.

Phase Identification of Nano-Phase Materials using Convergent Beam Electron Diffraction (CBED) Technique

  • Kim, Gyeung-Ho;Ahn, Jae-Pyoung
    • Applied Microscopy
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    • v.36 no.spc1
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    • pp.47-56
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    • 2006
  • Improvements are made to existing primitive cell volume measurement method to provide a real-time analysis capability for the phase analysis of nanocrystalline materials. Simplification is introduced in the primitive cell volume calculation leading to fast and reliable method for nano-phase identification and is applied to the phase analysis of Mo-Si-N nanocoating layer. In addition, comparison is made between real-time and film measurements for their accuracy of calculated primitive cell volume values and factors governing the accuracy of the method are determined. About 5% accuracy in primitive cell determination is obtained from camera length calibration and this technique is used to investigate the cell volume variation in WC-TiC core-shell microstructure. In addition to chemical compositional variation in core-shell type structure, primitive cell volume variation reveals additional information on lattice coherency strain across the interface.

A Study on Implementation of a Mission Computer based on COTS (상용 기성품 기반 항공기 임무컴퓨터 구현에 관한 연구)

  • Yang, Sung-Wook;Yang, Jun-Mo;Lee, Sang-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.22 no.4
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    • pp.81-86
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    • 2014
  • In the development of an avionics system, there is a trend of using commercial-off-the-shelf(COTS) equipments in order to reduce the development cost and time. In this paper, we present an implementation of an aircraft mission computer using the objected oriented software and the COTS equipments. We execute the aircraft guidance software on the system, and measure the calculation time and the used memory. To compare the guidance capability of the software program, we implement the same software logic on DS1104 system. The guidance software program executed on two different systems resulted in the almost identical simulation.

Syntheses and Absorption Spectra of Polymethine Cyanine Dyes Such as Squarylium and Croconium Dyes (Squarylium, Croconium계 기능성 색소의 합성과 흡수 스펙트라)

  • 김성훈;한선경;임용진
    • Textile Coloration and Finishing
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    • v.6 no.1
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    • pp.28-32
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    • 1994
  • The synthesis and absorption spectra of squarvlium(SQ) dyes and croconium(CR) dyes were .studied. Absorption spectra of SQ dye in various solvents exhibited a negative solvatochrornism. Thus, it was suggested that the structure of SQ dye may be a highly polar structure. The λ$_{max}$ of CR dyes undergoes a bathochromic shift of about 100nm compared with the corresponding SQ dyes. This shift can be calculated by the Pariser-Parr-Pople molecular orbital method. From the PPP MO calculation results, we found that SQ dye and CR dye have a almost same Highest Occupied Molecular Orbital(HOMO) level(SQ : -8.0eV, CR : -8.09eV). On the other hand, energy levels of Lowest Unoccupied Molecular Orbital(LUMO) of SQ and CR dyes are -4.09eV and -4.13eV respectively. Thus, replacement of five membered ring by four membered ring in SQ dye causes a large bathochromic shift.t.

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A Study of Reuse Module Generation Algorithm consider the Power Consumption for FPGA Technology Mapping (FPGA 기술 매핑을 위한 소모 전력을 고려한 재사용 모듈 생성 알고리즘에 관한 연구)

  • Youn, Choong-Mo;Kim, Jae-Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.12
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    • pp.2306-2310
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    • 2007
  • In this paper, reuse module generation algorithm consider the power consumption for FPGA technology mapping is proposed. To proposed algorithm is RT library generating algorithm, consider power consumption for reuse module using FPGA technology mapping. In the first, selected FPGA for power consumption calculation. Technology mapping process have minimum total power consumption consider LUT's constraint in selected FPGA. A circuit into device by selected proper modules of allocation result for power consumption constraint using data.

Optimum Condition on Overlap of Physical Properties of HIPS Samples

  • Son, Jung-Mo
    • Bulletin of the Korean Chemical Society
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    • v.12 no.1
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    • pp.52-57
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    • 1991
  • To find optimum conditions necessary in converting physical properties of any resin into those of others, eleven kinds of HIPS (High-Impact Polystyrene) resins were prepared. First physical properties of eleven samples divided into three groups are analyzed by a torque rheometer (named Plasti-Corder, Model No.: PLD 651) and GPC (Gel Permeation Chromatography), and then optimum conditions on conversion among samples are obtained by calculation from computer simulation so that any sample subjected to each group can show physical properties of other samples in its group. Even though the kind of plasticizer of any sample is different with others in its group, once optimum conditions on conversion among samples are met, it is found that physical properties of any sample are identical or similar to those of others in each group.

Nucleophilic Substitution Reactions of Thiopheneethyl Arenesulfonates with Anilines and N,N-Dimethylanilines

  • 오혁근;윤정환;조인호;이익준
    • Bulletin of the Korean Chemical Society
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    • v.18 no.4
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    • pp.390-394
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    • 1997
  • Nucleophilic substitution reactions of 2-thiopheneethyl benzenesulfonates (2-TEB) and 3-thiopheneethyl benzenesulfonates (3-TEB) with anilines and N,N-dimethylanilines (DMA) are investigated in acetonitrile at 60.0 ℃. The cross-interaction constants ρxz determined for the reactions with anilines are large negative (- 0.50) which are comparable to those for the similar predominantly frontside-attack SN2 reactions of 1-phenylethyl (1-PEB), 2-phenylethyl (2-PEB) and cumyl benzenesulfonates. A large negative ρxz value (- 0.4∼- 0.8) is considered to provide a mechanistic criterion for the frontside-attack SN2 mechanism with a four-center transition state. In agreement with this proposal the kinetic isotope effects, kH/kD, involving deuterated aniline nucleophiles are all greater than one reflecting partial N-H(D) bond cleavage in the transition state. The MO theoretical reactant structures of 1-PEB, 2-PEB and 2-TEB based on the PM3 calculation show that the benzene ring blocks the backside nucleophile approach to the reaction center carbon (Cα) enforcing the frontside-attack SN2 mechanism.

Semiempirical Molecular Orbital Calculations of the Substituent Effects on Acylations of 3-Cephem Analogues

  • Chang Moon-Ho;Koh Hun-Yeong;Lee Jung-Chull;Lee Yoon Sup
    • Bulletin of the Korean Chemical Society
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    • v.15 no.6
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    • pp.453-455
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    • 1994
  • Semiempirical MO calculations are applied to estimate the substituent effects on acylations of the nonfused N-vinyl-2-amino $\beta-lactams$ having frameworks analogous to 3-cephems. The stabilization energy for the reaction intermediate of the nucleophilic attack by the hydroxide ion is selected as the reactivity index and calculated by AM1 and PM3 methods for the model $\beta-lactams$ with substituents at the C1 and N-vinyl terminal positions. The reactivities are larger for -SH connected to the C1 and strong $\pi-acceptors$ at the N-vinyl terminal implying the large reactivity for known active cephalosporins. Quantum chemical calculation of stabilization energy could be useful in correlating antibiotic activities of many compounds obtained as derivatives of a lead compound.

MO Calculation for the Dissociative Adsorption of Oxygen Molecule on Ni44(111) Model Surface

  • Lee Kwang Soon;Koo Hyun Joo;Ahn Woon Sun
    • Bulletin of the Korean Chemical Society
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    • v.15 no.12
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    • pp.1093-1097
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    • 1994
  • The interaction of oxygen molecule with Ni44(111) model surface to which the molecule approaches is studied by calculating the relevant DOS and COOP with the tight-binding EHT method. It is found that the dissociative adsorption of oxygen takes place as a result of electron transfer from the Ni d${\pi}$ orbital to the antibonding 1${\pi}_g$ orbital of the oxygen molecule. This finding is noteworthy to contrast with the case of Ni(100) surface in which the electron transfer takes place from the Ni d${\delta}$ orbital of the nickel surface.