• Title/Summary/Keyword: Negative stability

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Comparison between Positive and Negative Ion Mode FAB CAD MS/MS Spectra of Linkage-Isomeric Oligosaccharides

  • Yoo, Eun-Sun
    • BMB Reports
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    • v.30 no.4
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    • pp.253-257
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    • 1997
  • Negative ion fast atom bombardment (FAB) mass spectra were found to allow the determination of the linkage positions in a series of underivatized linkage-isomeric oligosaccharides. A previous work (Laine et al., 1988) reported that ion patterns of linkage-isomeric trisaccharides could be distinguished by a positive ion. Negative ion FAB collison-activated dissociation (CAD) mass spectrometry (MS) spectra of trisaccharides exhibited better sensitivity than the positive ion mode and provided specific fragmentation patterns according to the linkage positions. Especially, the fragmentations, m/z 205 in F6 and m/z 221 in G6, not occuring in 1-3 or 1-4 linkage. were an indication of 1-6 linkage, by changing collision energies from + 10 eV to +60 eV. The survival ratios of molecular ions in each collision energy set gave support to previous results in which the order of bond stability was 1-6>1-4>1-3 linkage.

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ON THE RECURSIVE SEQUENCE X_{n+1} = $\alpha$ - (X_n/X_n-1)

  • YAN XING XUE;LI WAN TONG;ZHAO ZHU
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.269-282
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    • 2005
  • We study the global asymptotic stability, global attractivity, boundedness character, and periodic nature of all positive solutions and all negative solutions of the difference equation $$x_{n+1}\;=\;{\alpha}-{\frac{x_{n-1}}{x_{n}},\;n=0,1,\;{\cdots}$$, where ${\alpha}\;\in\; R$ is a real number, and the initial conditions $x_{-1},\;x_0$ are arbitrary real numbers.

MULTIPLICITY AND STABILITY OF SOLUTIONS FOR SEMILINEAR ELLIPTIC EQUATIONS HAVING NOT NON-NEGATIVE MASS

  • Kim, Wan-Se;Ko, Bong-Soo
    • Journal of the Korean Mathematical Society
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    • v.37 no.1
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    • pp.85-109
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    • 2000
  • In this paper, the multiplicity, stability and the structure of classical solutions of semilinear elliptic equations of the form (equation omitted) will be discussed. Here $\Omega$ is a smooth and bounded domain in $R^{n}$ (n $\geq$ 1), f(x,u) = │u│$^{\alpha}$/sgn(u)-h(x), 0 < $\alpha$ < 1, (n $\geq$ 1) and h is a ${\gamma}$- Holder continuous function on $\Omega$ for some 0 < ${\gamma}$ < 1.a}$ < 1.

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A Stability on the Solvents of Spectral Sensitizer for Photographic Emulsion (사진유제용 분광증감색소의 용매에 대한 안정성)

  • Kim, Yeoung-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.14 no.2
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    • pp.65-70
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    • 1997
  • The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was $600nm{\sim}612nm$. But it was identified that only methanol can be used to photographic emulsion.

The Molecular Mechanics Evaluation of the Stability of Bridgehead Olefins Containing Medium Rings

  • 김장섭
    • Bulletin of the Korean Chemical Society
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    • v.18 no.5
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    • pp.488-495
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    • 1997
  • The stability of bridgehead olefins containing 8 and 10 membered rings has been investigated by the MMX molecular mechanics calculation together with the GMMX conformational searching program. A number of 'hyperstable' bridgehead olefins, which have negative olefin strain values, have been found from the calculated values of strain energy and olefin strain for the series of in- and out-bicyclo[n.3.3]alk-1-ene and in- and out-bicyclo[n.4.4]alk-1-ene (n=1 to 8). For the bridgehead olefins with 'out' topology, hyperstable olefins were found in the systems having cyclononene or larger rings. For the bridgehead olefins with 'in' topology, hyperstable olefins were found in the systems having cyclodecene or larger rings.

ASYMPTOTIC STABILIZATION FOR A DISPERSIVE-DISSIPATIVE EQUATION WITH TIME-DEPENDENT DAMPING TERMS

  • Yi, Su-Cheol
    • Journal of the Chungcheong Mathematical Society
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    • v.33 no.4
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    • pp.445-468
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    • 2020
  • A long-time behavior of global solutions for a dispersive-dissipative equation with time-dependent damping terms is investigated under null Dirichlet boundary condition. By virtue of an appropriate new Lyapunov function and the Lojasiewicz-Simon inequality, we show that any global bounded solution converges to a steady state and get the rate of convergence as well, when damping coefficients are integrally positive and positive-negative, respectively. Moreover, under the assumptions on on-off or sign-changing damping, we derive an asymptotic stability of solutions.

Wind load and wind-induced effect of the large wind turbine tower-blade system considering blade yaw and interference

  • Ke, S.T.;Wang, X.H.;Ge, Y.J.
    • Wind and Structures
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    • v.28 no.2
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    • pp.71-87
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    • 2019
  • The yaw and interference effects of blades affect aerodynamic performance of large wind turbine system significantly, thus influencing wind-induced response and stability performance of the tower-blade system. In this study, the 5MW wind turbine which was developed by Nanjing University of Aeronautics and Astronautics (NUAA) was chosen as the research object. Large eddy simulation on flow field and aerodynamics of its wind turbine system with different yaw angles($0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$ and $45^{\circ}$) under the most unfavorable blade position was carried out. Results were compared with codes and measurement results at home and abroad, which verified validity of large eddy simulation. On this basis, effects of yaw angle on average wind pressure, fluctuating wind pressure, lift coefficient, resistance coefficient,streaming and wake characteristics on different interference zone of tower of wind turbine were analyzed. Next, the blade-cabin-tower-foundation integrated coupling model of the large wind turbine was constructed based on finite element method. Dynamic characteristics, wind-induced response and stability performance of the wind turbine structural system under different yaw angle were analyzed systematically. Research results demonstrate that with the increase of yaw angle, the maximum negative pressure and extreme negative pressure of the significant interference zone of the tower present a V-shaped variation trend, whereas the layer resistance coefficient increases gradually. By contrast, the maximum negative pressure, extreme negative pressure and layer resistance coefficient of the non-interference zone remain basically same. Effects of streaming and wake weaken gradually. When the yaw angle increases to $45^{\circ}$, aerodynamic force of the tower is close with that when there's no blade yaw and interference. As the height of significant interference zone increases, layer resistance coefficient decreases firstly and then increases under different yaw angles. Maximum means and mean square error (MSE) of radial displacement under different yaw angles all occur at circumferential $0^{\circ}$ and $180^{\circ}$ of the tower. The maximum bending moment at tower bottom is at circumferential $20^{\circ}$. When the yaw angle is $0^{\circ}$, the maximum downwind displacement responses of different blades are higher than 2.7 m. With the increase of yaw angle, MSEs of radial displacement at tower top, downwind displacement of blades, internal force at blade roots all decrease gradually, while the critical wind speed decreases firstly and then increases and finally decreases. The comprehensive analysis shows that the worst aerodynamic performance and wind-induced response of the wind turbine system are achieved when the yaw angle is $0^{\circ}$, whereas the worst stability performance and ultimate bearing capacity are achieved when the yaw angle is $45^{\circ}$.

Factors associated with Marital Satisfaction and Stability of Married Men and Women (기혼남녀의 결혼만족도와 안정성에 관련된 요인)

  • Hwang, Jong-Gui
    • Korean Journal of Human Ecology
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    • v.18 no.4
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    • pp.825-840
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    • 2009
  • The purpose of this study is to investigate the factors associated with marital satisfaction and stability among married men and women. The major findings of this study are as follows: the factors associated with marital satisfaction and stability are different between gender. For married women the positive communication with spouse strongly had positive effect on women's marital satisfaction, while destructive conflict strongly had negative effect on women's marital stability. Otherwise, married men's positive communication with spouse was the most important factor in the marital satisfaction. The emotional support of family-of-origin strongly had effect on men's marital stability. This study reveals that the emotional support from families of origin have a direct effect on needs for affection and autonomy, positive communication, destructive conflict patterns, sexual satisfaction, marital satisfaction and stability. Therefore, the results could be useful resources for family counselors and researchers to develop educational program for married couples.

A Study on Changes in Appendage Design for Improvement of Dynamic Stability of Manta-type Unmanned Undersea Vehicle (Manta형 무인잠수정의 동안정성 향상을 위한 부가물의 설계 변경에 관한 연구)

  • Bae, Jun-Young;Sohn, Kyoung-Ho;Kwon, Hyeong-Ki;Lee, Seung-Keon
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.3 s.153
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    • pp.323-331
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    • 2007
  • Proposed Manta-type Unmanned Undersea Vehicle(UUV) turned out to have the tendency of dynamic instability in vertical plane, and moreover to have that of so strong dynamic stability in horizontal plane as to cause another problem in turning motion due to negative value of sway damping lever. The authors discussed the changes in appendage design for improvement of dynamic stability of UUV in vertical and horizontal planes. As a result, the dynamic stability in vertical plane was improved by increasing the area of horizontal stern planes. and the dynamic stability in horizontal plane was also improved by removal of lower vertical plate and by adjusting the area and position of upper vertical plate simultaneously.

Nexus among Bank Competition, Efficiency and Financial Stability: A Comprehensive Study in Bangladesh

  • RAHMAN, Syed Mohammad Khaled;CHOWDHURY, Mohammad Ashraful Ferdous;TANIA, Tasmina Chowdhury
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.317-328
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    • 2021
  • This study examines the impact of bank competition and efficiency in the financial stability of the banking sector in Bangladesh. The study used the Lerner index and the Boone indicator to represent the bank competition, while the non-performing loan (NPL) and Z-score are used to represent financial stability. The secondary data were collected from the annual reports of 28 DSE listed commercial banks of Bangladesh over the period from 2011 to 2018. Using a dynamic panel GMM model, the study found the Lerner index is significantly negatively related with Z-score, which means that higher bank competition results in higher bank stability. It is also seen that higher cost efficiency results in higher bank stability. The Lerner index has negative, but insignificant impact on NPL. Similarly, using the Boone indicator, this study found that lower competition increases NPL. In terms of the Z-score, the Boone indicator found that 1 unit of increment results in decrease of the Z-score by 6.15 units. The study suggests that, as more competition results in more financial soundness, the banking industry competition should be ensured by policymakers or regulators. Banks could enhance financial stability by cost control to achieve cost efficiency as well as by improving loan-to-asset ratio.