• Title/Summary/Keyword: Level shift

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Cesium Frequency Standard Based on a Continuous Slow Atomic Beam (연속 저속 원자빔을 이용한 세슘 주파수 표준기)

  • Lee, Ho-Sung;Park, Sang-Eon;Kwon, Taek-Yong;Yang, Sung-Hoon;Cho, Hyuk
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.08a
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    • pp.194-195
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    • 2000
  • Laser-cooled slow atoms can lead to a considerable improvement in both the accuracy and the frequency stability of atomic frequency standards. Most of the developed frequency standards with the slow atoms use atomic fountain scheme that includes pulsed atomic beam. Although this type of frequency standard has already demonstrated the accuracy about 10$^{-15}$ level$^{(1)}$ , a continuous beam of slow atoms may become an alternative approach, because the pulsed operation of the atomic fountain has some drawbacks such as the collisional shift and the limitation in the short-term frequency stability. (omitted)

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Genetic Variation in Exon 3 of Human Apo B mRNA Editing Protein (apobec-1) Gene

  • Hong, Seung-Ho;Song, Jung-Han;Kim, Jin-Q
    • Journal of Genetic Medicine
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    • v.3 no.1
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    • pp.15-19
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    • 1999
  • We have investigated the genetic variation in the human apo B mRNA editing protein (apobec-1) gene. Exon 3 of the apobec-1 gene was amplified by polymerase chain reaction. After detection of an additional band by single strand conformational polymorphism (SSCP) analysis, sequencing of the SSCP-shift sample revealed a single-base mutation. The mutation was a CGG transversion at codon 80 resulting in a lleRMet substitution. This substitution was confirmed by restriction fragment length polymorphism analysis since a Pvull site is abolished by the substitution. Population and family studies confirmed that the inheritance of the genotypes for apobec-1 gene polymorphism is controlled by two codominant alleles (P1 and P2). A significant difference in plasma triglyceride was detected among the different apobec-1 genotypes in the CAD patients (P<0.05). Our study could provide the basis for elucidating the interaction between genetic variation of the apobec-1 gene and disorders related to lipid metabolism.

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Ab initio Studies on Rh(I)- and Ir(I)-Phenylacetylene Complexes

  • 문정현;최은석;강성권
    • Bulletin of the Korean Chemical Society
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    • v.19 no.5
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    • pp.557-560
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    • 1998
  • The structures and energies for the intramolecular rearrangement in $d^8-MCl(PH_3)_2$(HC≡CPh), M=Rh and Ir, complexes were studied by ab initio method at the Hartree-Fock and MP2 levels of theory. Three transition states in two pathways were optimized and characterized by frequency calculations. The activation energies for the process of π-type complex 1 to hydrido-alkynyl 2 have been computed to be relatively low 6.97 and 21.33 kcal/mol at MP2 level for Rh and Ir metals, respectively. However, the activation energies for a 1,2-hydrogen shift via t.s.3 have been computed to be high 50.83 and 60.05 kcal/mol for Rh and Ir metals.

The Electronic Structure of Methanethiol Adsorbed on Silver Surface: An Extended Huckel Study

  • Hwang, Sun-Gu;Jang, Yun-Hee;Kim, Ho-Jing
    • Bulletin of the Korean Chemical Society
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    • v.12 no.6
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    • pp.635-643
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    • 1991
  • The adsorption of methanethiol on a Ag(100) surface has been studied with Extended Huckel calculation in the cluster approximation of the substrate. Since it has been known that methanethiol is chemisorbed dissociatively on silver surface by rupture of S-H bond, the methanethiolate radical is taken as adsorbate. Of the various adsorption sites, the 4-fold hollow site is preferred. The methanethiolate radical is mainly adsorbed via its 2e orbital. The charge transfer from metal to this level leads to the C-S bond weakening, which is consistent with the red shift of C-S stretching mode in surface enhanced Raman (SER) spectrum.

Smart Divide and the Paradigm Shift of Social Capital

  • Lee, Seungmin
    • Journal of Information Science Theory and Practice
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    • v.9 no.3
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    • pp.1-13
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    • 2021
  • In the current smart device-based information environment, information utilization is closely related to social capital. Additionally, the smart divide that occurs owing to the differences in use of smart devices has a significant influence on social capital. In this respect, this research empirically analyzed how the smart divide affects social capital construction. The study found that the level of and proficiency in using smart devices and diversity of the information formats used through smart devices affect social capital construction. Further, people who fully utilize smart devices can enhance their participation in social activities, social networks, and reciprocal activities, leading people to construct social capital in a wider range. Contrarily, those who are unable to use smart devices adequately may be disadvantaged in terms of the opportunity to construct social capital and share public interests. Thus, to maximize the intrinsic value of social capital, it is necessary to consider the factors of the smart divide as a complicated and multi-faceted digital divide and the ways to utilize social capital as a driving force for integrating society, and not as a mechanism for dividing members of society.

PMO Theory of Orbital Interactions (Part 7). $\sigma-\pi$ Interactions

  • Kong, Byung-Hoo;Lee, Byung-Choon;Lee, Ik-Choon;Yang, Ki-Yull
    • Bulletin of the Korean Chemical Society
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    • v.6 no.5
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    • pp.277-279
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    • 1985
  • Orbital interactions of the types, ${\sigma}-{\pi},\;{\sigma}^*-{\pi},\;{\sigma}-{\pi}^*\;and\;{\sigma}^*-{\pi}^*$ are investigated for the rotamers of ${\alpha}$-X-acetones (X = F and Cl) using STO-3G method of calculation. It was found that the interactions are possible only in gauche forms, and the ${\sigma}^*-{\pi}^*$ interactions are in general greater than the $\sigma-\pi$ interactions due to the greater overlap, in spite of the greater energy gap involved; the greater ${\sigma}^*-{\pi}^*$ interaction causes greater lowering of ${\pi}^*$ level relative to the lowering of ${\sigma}$ in the ${\sigma}-{\pi}$ interaction so that both ${\sigma}-{\pi}^*$ and $n-{\pi}^*$ interactions are enhanced in the gauche forms. The extra stability of the gauche form and the red shift in the $n-{\pi}^*$ transition are thus found to be natural corollaries of the greater ${\sigma}^*-{\pi}^*$ interaction in the gauche forms.

Phase Control Optimization at Waveguide Crossover and Its Application to 45° Optical Hybrid for Demodulating 8DPSK Optical Signals

  • Jeong, Seok-Hwan
    • Current Optics and Photonics
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    • v.5 no.6
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    • pp.711-720
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    • 2021
  • A novel optical hybrid device that doubles the multilevel demodulation resolution by adding the optical interferometer with a waveguide crossover is proposed, theoretically analyzed and experimentally verified. We report two types of all-passive phase control schemes that will be referred to as a phase compensation scheme and a phase optimization scheme. We also apply the proposed phase control schemes to a 45° optical hybrid consisting of two parallel 90° optical hybrids together with the proposed phase control scheme for demodulating 8-level differential phase shift keying optical signals. Octagonal phase response with low wavelength sensitive excess loss of <0.8 dB over 31-nm-wide spectral range will be demonstrated in the InP-based material platform.

Post-disturbance Recovery Pattern in the Soft Corals-Macroalgae Mixed Habitat in Jeju Island, Korea

  • Kim, Junsu;Hong, Seokwoo;Yang, Kwon Mo;Macias, Daniela;Kim, Jeong Ha
    • Journal of Marine Life Science
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    • v.6 no.2
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    • pp.117-123
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    • 2021
  • Post-disturbance recovery pattern of subtidal soft corals-macroalgae mixed community and the role of water depth were investigated. The experiment was conducted in a subtidal rock wall of Munseom, Jeju Island, Korea for 2.5 years. Artificial disturbance was done at established treatment plots at depths of 10, 15 and 20 m and were then compared with undisturbed control plots. After disturbance, recovery of soft corals was very slow, whereas macroalgae quickly occupied the plots and reached a similar level as the control in 6 months, and this pattern was consistent at all water depths. This unbalanced speed of recovery caused higher macroalgae establishment than soft corals in treatment compared to control plots, indicating a possible phase shift in the community structure. This study provides an important implication for the necessity of monitoring the influence of disturbance at a larger scale, from a conservation perspective of soft corals in Jeju coast.

Effect of Energy Consumptuon on Air Pollution in I.R.Iran

  • Ayati, B.;Ganjidoust, H.
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.43-46
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    • 2003
  • The economy of I.R.Iran is so related to oil that has had many environmental problems especially air pollution in urban areas in recent years. Statistics show that most of the time, the condition of air quality is in crisis level especially during fall and winter seasons. Rapid and high population growth has had large amount of fossil fuels consumption in all sectors including transportation, industry, agriculture, residential and commercial and public services and air pollution and healthy problems. Iran's abundance of fossil fuel resources has tended to discourage the country's incentive to shift to cleaner alternative energy sources for its energy needs that must be considered in future programming. These are discussed in this paper.

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Introducing the Concept of Intelligent Financial Inclusion

  • Anam Yasir;Alia Ahmed
    • International Journal of Computer Science & Network Security
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    • v.23 no.4
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    • pp.103-110
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    • 2023
  • Financial inclusion is the safe and timely access of formal financial services to people at affordable costs. Various barriers of legacy financial system hinder the involvement of all segments of populations in the financial sector. The journey from financial exclusion to financial inclusion has to be achieved with the implementation of technological breakthroughs. Covid-19 has also raised the need for technology in all sectors of the economy. This research paper introduces the concept of intelligent financial inclusion which is the provision of financial services to people with the help of intelligent systems. This intelligent system will take the concepts from the human mind, cognitive sciences, and artificial intelligence tools and techniques. For achieving the optimal level of financial inclusion, economies must shift their financial sector from traditional means to intelligent financial systems. In this way, intelligent financial inclusion will achieve the target of involving all people in the financial sector.