• Title/Summary/Keyword: Negative Stability

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Relationship between Job Stress and Burnout for Noncommissioned Officers: Focusing on Mediating Effects of Coworker Support and Emotional Stability (부사관의 직무스트레스와 소진간의 관계 : 동료 지지와 정서적 안정성의 매개효과를 중심으로)

  • Lee, Jayoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.243-249
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    • 2018
  • The purpose of this study was to investigate the relationship between job stress, coworker support, emotional stability and burnout, and to examine the mediating effect of coworker support and emotional stability. A total of 212 noncommissioned officers were interviewed and correlation and mediating effect analysis were applied to the resulting data. As a result, the job stress showed a positive correlation with coworker support, emotional stability and negative correlation with burnout, and coworker support and emotional stability showed a negative correlation with burnout. In addition, coworker support and emotional stability were partially mediated by job stress and burnout. However, in order to examine the relationship between these two, the double mediation between job stress and burnout showed that the emotional stability of job stress was partially mediated directly by burnout, and that coworker support was mediated by burnout only through emotional stability. Based on these results, the implications and limitations of this study were discussed.

Negative DC-shift Instability in Hybrid Rocket (하이브리드 로켓에서의 Negative DC-shift 발생 특성)

  • Kang, Dong-Hoon;Lee, Chang-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.11a
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    • pp.522-525
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    • 2009
  • DC-shift phenomenon can be observed in Hybrid rocket combustion. This phenomenon makes performance drop which is structure problem or reduce thrust. Understanding of DC-shift phenomenon, the condition of the hybrid rocket combustion stability can be found. In this paper, the condition of Negative DC-shift was found and made by changing oxidizer flow with pre-post chamber. The Negative C-shift phenomenon and characteristic were defined from the experimental study.

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The effect of negative bias stress stability in high mobility In-Ga-O TFTs

  • Jo, Kwang-Min;Sung, Sang-Yun;You, Jae-Lok;Kim, Se-Yun;Lee, Joon-Hyung;Kim, Jeong-Joo;Heo, Young-Woo
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2013.05a
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    • pp.154-154
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    • 2013
  • In this work, we investigated the characteristics and the effects of light on the negative gate bias stress stability (NBS) in high mobility polycrystalline IGO TFTs. IGO TFT showed a high drain current on/off ratio of ${\sim}10^9$, a field-effect mobility of $114cm^2/Vs$, a threshold voltage of -4V, and a subthresholdslpe(SS) of 0.28V/decade from log($I_{DS}$) vs $V_{GS}$. IGO TFTs showed large negative $V_{TH}$ shift(17V) at light power of $5mW/cm^2$ with negative gate bias stress of -10V for 10000seconds, at a fixed drain voltage ($V_{DS}$) of 0.5V.

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Centrifuge Model Experiments and Numerical Analyses of the Behavior of Excavated Marine Clay Slope (해성점토 굴착사면의 거동에 관한 원심모형실험 및 수치해석)

  • Park, Byung-Soo
    • Journal of Ocean Engineering and Technology
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    • v.20 no.5 s.72
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    • pp.49-56
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    • 2006
  • In this thesis, centrifuge model experiments and numerical analyses were carried out to investigate the behavior of an excavated slope in soft clay ground. Centrifuge model tests were performed with various slopes for the excavated ground, such as 1:1.5 and 1:2. Pore pressuresthe model ground were measured to find their effects on the stability of the excavated slope. These experiments showed that the model with 1:2.5 maintained its stability within a short period of time and failed gradually. Therefore, anexcavated slope of soft soil with this slope might maintain stable conditions within a certain time. The mode1 with a 1:3 slope was observed to maintain a very stable condition, showing insignificant deformation in the ground after being excavated. Numerical analyses with PLAXIS, a commerciallyavailable software implemented with the finite element numerical technique, were performed to find the pore pressure distribution within the ground mass and the deformation of the soil. From the results of numerical analysis, a negative pore pressure was developed after the excavation and thus the stability of the slope was maintained. The safety factor for slope failure was found to decrease with time because of the dissipation of negative pore pressure with time.

STABILITY ANALYSIS FOR PREDATOR-PREY SYSTEMS

  • Shim, Seong-A
    • The Pure and Applied Mathematics
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    • v.17 no.3
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    • pp.211-229
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    • 2010
  • Various types of predator-prey systems are studied in terms of the stabilities of their steady-states. Necessary conditions for the existences of non-negative constant steady-states for those systems are obtained. The linearized stabilities of the non-negative constant steady-states for the predator-prey system with monotone response functions are analyzed. The predator-prey system with non-monotone response functions are also investigated for the linearized stabilities of the positive constant steady-states.

Eigenstructure-Based Robust Stability Criterion for Linear Time-Varying Systems

  • Lee, Ho-Chul;Park, Jae-Weon
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.44.3-44
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    • 2002
  • Stability robustness of a linear time-varying system with time-varying structured state space uncertainties is considered by using extended-mean theorem and Bellman's lemma. The extended-mean theorem is a necessary and sufficient exponential stability criterion based on the recently developed PD-eigenvalue and PD-eigenvector for a linear time-varying system. Our new result required that the extended-mean of each nominal PD-eigenvalue should be negative real which is determined by a norm involving the structures of the uncertainty and the no...

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A Case Study on the Stability Evaluation of Piles for Negative Skin Eviction by the LRFD Approach (LRFD설계법에 의한 부마찰력이 작용하는 말뚝의 안정성 평가 사례 연구)

  • Cho Chun-Whan;Kim Woong-Kyu;Lee Woo-Chel
    • Journal of the Korean Geotechnical Society
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    • v.21 no.5
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    • pp.123-131
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    • 2005
  • Recently, construction activities in reclaimed onshore areas increase in our country In this case, the stability evaluation of the piles for negative skin friction is an important factor for the design of pile foundation in soft grounds. Nevertheless, the design of piles for negative skin friction (or downdrag forces) is probably poorly understood by many geotechnical engineers. It is mainly because only the bearing capacity aspect is taken into account for the downdrag evaluation of piles in most of design specifications. However, the problems fur negative skin friction of piles are mostly related with settlement rather than bearing capacity Meanwhile, LRFD (Load Resistance Factor Design) approach considers both ultimate limit state in terms of bearing capacity and serviceability limit state in terms of settlements. This paper proposes LRFD approach for the downdrag evaluation of piles and compares this approach to traditional design approach. And also a case history is analyzed. Through the analysis some suggestions to solve the problems for the design of piles for negative skin friction are suggested.

Effect of Heat Treatment on the Dimensional Stability and the Bending Properties of Radiata Pine Sapwood

  • Yun, Ki-Eon;Kim, Gyu-Hyeok;Kim, Jae-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.27 no.4
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    • pp.30-37
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    • 1999
  • The effects of heat treatment on the dimensional stability and bending properties of radiata pine sapwood were investigated. The dimensional stability was almost achieved by heat treatment though the loss of strength was accompanied as a negative effect. The improvement in dimensional stability of wood and the resultant reduction in bending properties were closely related to treatment temperature and duration. The optimum treatment conditions, which could be used to achieve a desired improvement in dimensional stability with resultant losses in modulus of rupture were proposed based on the results obtained in this study.

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