• Title/Summary/Keyword: self-consistent method

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DETERMINATION OF NORMAL VECTORS FOR BOUNDARIES OF PLASMAS BASED UPON RANKINE-HUGONIOT RELATIONS ESTIMATED WITH A SINGLE SPACECRAFT

  • Soen, J.
    • Journal of Astronomy and Space Sciences
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    • v.15 no.1
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    • pp.111-118
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    • 1998
  • A method to determine normal vectors for boundaries of plasmas with a series of data acquired from a single spacecraft is investigated. The determination of the normal vector is possible through a set of Rankine-Hugoniot(R-H) relations that are conser-vation relations of plasmas across a boundary. It is assumed that the boundary is planar and that the structure of the boundary is not varing in the rest frame of plasmas. The present method utilizes a complete set of R-H relations and provieds self-consistent predictions of the plasma densities, bulk velocities, and temperatures a s well as mag-netic fields. It is expected that the present method provides a more accurate normal vector than the previous methods which employ only subsets of the available R-H relations.

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Consistent inflow boundary conditions for modelling the neutral equilibrium atmospheric boundary layer for the SST k-ω model

  • Yang, Yi;Xie, Zhuangning;Gu, Ming
    • Wind and Structures
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    • v.24 no.5
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    • pp.465-480
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    • 2017
  • Modelling an equilibrium atmospheric boundary layer (ABL) in computational wind engineering (CWE) and relevant areas requires the boundary conditions, the turbulence model and associated constants to be consistent with each other. Among them, the inflow boundary conditions play an important role and determine whether the equations of the turbulence model are satisfied in the whole domain. In this paper, the idea of modeling an equilibrium ABL through specifying proper inflow boundary conditions is extended to the SST $k-{\omega}$ model, which is regarded as a better RANS model for simulating the blunt body flow than the standard $k-{\varepsilon}$ model. Two new sets of inflow boundary conditions corresponding to different descriptions of the inflow velocity profiles, the logarithmic law and the power law respectively, are then theoretically proposed and numerically verified. A method of determining the undetermined constants and a set of parameter system are then given, which are suitable for the standard wind terrains defined in the wind load code. Finally, the full inflow boundary condition equations considering the scale effect are presented for the purpose of general use.

Conformational Preference of Pseudo-Proline Dipeptide in the Gas Phase and Solutions

  • Park, Hae-Sook;Kang, Young-Kee
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.74-74
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    • 2003
  • We report here the results on N-acetyl-N'-methylamide of oxazolidine (Ac-Oxa-NHMe) calculated using the ab initio molecular orbital method with the self-consistent reaction field (SCRF) theory at the HF level of theory with the 6-3l+G(d) basis set. The displacement of the $\square$-CH$_2$ group in proline ring by oxygen atom has affected the structure of proline, cis$\^$∼/ trans equilibrium, and rotational barrier. The up-puckered structure is found to be prevalent for the trans conformers of the Oxa amide. The higher cis populations of the Oxa amide can be interpreted due to the longer distance between the acetyl methyl group and the 5-methylene group of the ring for the trans conformer of the Oxa amide than that of the Pro amide. The changes in charge of the prolyl nitrogen and the decrease in electron overlap of the C$\^$∼/ N bond for TS structures seem to play a role in lowering rotational barriers of the Oxa amide compared to that of the Pro amide. The calculated preferences for cis conformers in the order of Oxa > Pro amides and for trans-to-cis rotational barriers in the order of Pro > Oxa amide in water are consistent with experimental results on Oxa-containing peptides. The pertinent distance between the prolyl nitrogen and the N$\^$∼/ H amide group to form a hydrogen bond might indicate that this intramolecular hydrogen bond could contribute in stabilizing the TS structures of Oxa and Pro amides and play a role in prolyl isomerization.

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Evaluation of Crack Self-healing Performance in Centrifugal Molding Concrete by Permeability Test (원심성형 콘크리트의 투수시험을 통한 균열 자기치유 성능평가)

  • Hwang, Chul Sung;Woo, Hae Sik;Choi, Young Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.3
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    • pp.84-89
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    • 2018
  • Recently, study on self-healing materials have been performed to increase the life by repairing the damage of structures themselves, which are difficult to repair or require high maintenance costs. A water permeability test has been widely used for the evaluation of self-healing performance. However, in the self-healing performance test method, the initial crack width of the concrete greatly affects on the self-healing performance but it does not have a consistent standard. Therefore, in this study, the correlation between crack and permeability and that between time and permeability were analyzed based on crack width and permeability. In addition, since the initial crack width measured by optical microscope is not reliable, the value is derived from the Poiseuille flow and the tendency of time-permeability and time-crack width are analyzed.

Analysis of Motivational Interviewing to Overcome Psychological Insulin Resistance of Type 2 Diabetes (제2형 당뇨병 환자의 심리적 인슐린저항성 극복을 위한 동기강화상담 분석)

  • Lee, Hyunjin;Cho, JeongHwa;Song, Youngshin
    • Journal of the Korea Convergence Society
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    • v.9 no.12
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    • pp.485-493
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    • 2018
  • This study analyzed the motivational interviewing of type 2 diabetes patients in order to understand the difficulties and motivations associated with starting insulin treatment in psychosomatic insulin-resistant patients. The method used the consistent comparative analysis. The results of study were as follows: building relationships, focusing (Self-explore of problems with diabetes self-management, Recognizing the limitations of diabetes management, Concerns about complications, Imagine the future), inducing (Imagine the expected benefits and disadvantages of insulin administration, Discovering the benefits of insulin, Changes in thinking about starting insulin therapy), planning (Show specific curiosity about change, Planning change), maintaining change behavior (Keeping change confident), and evaluating. This study will contribute to understanding patients with type 2 diabetes with psychological insulin resistance. It may also provide implications for professionals helping these subjects.

Studies on the Adsorption Modeling of Cationic Heavy Metals(Pb, Cd) by the Surface Complexation Model (Surface Complexation Model을 이용한 양이온 중금속(Pb, Cd) 흡착반응의 모델화 연구)

  • 신용일;박상원
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.211-219
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    • 1999
  • Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values. In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(II) and Cd(II). Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.

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Optimum Design of Dye-Sensitized Solar Module for Building-Integrated Photovoltaic Systems

  • Lee, Kyu-Seok;Kang, Man Gu
    • ETRI Journal
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    • v.39 no.6
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    • pp.859-865
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    • 2017
  • This paper presents a method for determining the optimum active-area width (OAW) of solar cells in a module architecture. The current density-voltage curve of a reference cell with a narrow active-area width is used to reproduce the current density profile in the test cell whose active area width is to be optimized. We obtained self-consistent current density and electric potential profiles from iterative calculations of both properties, considering the distributed resistance of the contact layers. Further, we determined the OAW that yields the maximum efficiency by calculating efficiency as a function of the active-area width. The proposed method can be applied to the design of the active area of a dye-sensitized solar cell in Z-type series connection modules for indoor and building-integrated photovoltaic systems. Our calculations predicted that OAW increases as the sheet resistances of the contact layers and the intensity of light decrease.

All-Electron Relativistic SCF Calculations for Light Atoms and Diatomic Molecules; Correct Nonrelativistic Limit Calculations with a Relativistic Method

  • Baeck, Kyoung-Koo;Lee, Yoon-Sup
    • Bulletin of the Korean Chemical Society
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    • v.12 no.6
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    • pp.699-705
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    • 1991
  • Procedures to perform reliable relativistic self-consistent-field (RSCF) calculations are described. Using light atoms and molecules, it is demonstrated that the present method always yields correct nonrelativistic limit by employing a sufficiently large value for the speed of light in RSCF calculations. Many problems associated with analytic expansions of the Dirac equations can be computationally avoided by kinetically balancing the basis sets for large and small component spinors. Results of RSCF calculations for Ne, Kr, $H_2$, and LiH indicate very small relativistic effects for these systems as expected. Trends found is these molecules, however, may be useful in understanding relativistic effects for molecules with similar valence electronic structures and heavier atoms.

Simulation Method for Radio-Frequency Single-Electron Transistor (RF-SET) Operation (고주파 단일전자 트랜지스터 (RF-SET) 동작의 시뮬레이션 방법)

  • Yu Yun Seop;Park Hyun-Sik
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.5 s.335
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    • pp.9-14
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    • 2005
  • Simulation method for a pure radio-frequency (rf) mode of reflection-type and a pure rf mode of transmission-type radio-frequency single-electron transistor (RF-SET) operation is introduced. In this method, the solutions of differential equations based on Kirchhoff's law are obtained self-consistently at frequency-domain. Also, the steady-sate single-electron transistor (SET) current model and the time-dependent SET current model are used in this method. The reflected wave of a typical reflection-type RF-SET and the transmitted wave of a typical transmission-type RF-SET are calculated, and the accuracy of our developed method including the steady-state SET current model is verified with the method introduced by reference 2. At high frequency over GHz, results of our developed method including the time-dependent SET current model are considerably different from that including the steady-state SET current model. At high frequency over GHz, an exact time-dependent SET current model is needed to analyze RF-SET operation.

How do Lung Cancer Patients Experience Stigma?: A Meta-synthesis of Qualitative Studies

  • Jeong, Ji Yeon;Jeong, Gyeonghui;So, Hyang Sook
    • Korean Journal of Adult Nursing
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    • v.28 no.1
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    • pp.116-126
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    • 2016
  • Purpose: Lung cancer patients are often stigmatized since lung cancer is closely associated with smoking, which is a self-administered life style. The stigma of lung cancer has been examined in some qualitative studies; however, their findings were diverse and not yet synthesized. Therefore, this meta-synthesis study aimed to explore how lung cancer patients experience stigma. Methods: A meta-synthesis method, as suggested by Sandelowski and Barroso in 2007, was applied by aggregating the findings after an evaluation according to consolidated criteria for reporting qualitative research (COREQ). Results: By synthesizing the findings of the selected seven papers, a synthesized theme was emerged as "experiencing external and internal distances, which mandates authentic and consistent supports." The four sub-themes included 'experiencing some distance from the surrounded world,' 'experiencing self-made distance between the disease and oneself,' 'the disease experience causes social isolation and loneliness,' and 'there is lack of supportive care for myself.' Conclusion: Health care providers should be more attentive to supporting lung cancer patients by providing more effective advocacy programs that improve patients' quality of life.