• Title/Summary/Keyword: Curvilinearity

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Accuracy of maximal expiratory flow-volume curve curvilinearity and fractional exhaled nitric oxide for detection of children with atopic asthma

  • Park, Sang Hoo;Im, Min Ji;Eom, Sang-Yong;Hahn, Youn-Soo
    • Clinical and Experimental Pediatrics
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    • v.60 no.9
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    • pp.290-295
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    • 2017
  • Purpose: Airway pathology in children with atopic asthma can be reflected by the concave shape of the maximal expiratory flow-volume (MEFV) curve and high fractional exhaled nitric oxide (FeNO) values. We evaluated the capacity of the curvilinearity of the MEFV curve, FeNO, and their combination to distinguish subjects with atopic asthma from healthy individuals. Methods: FeNO and angle ${\beta}$, which characterizes the general configuration of the MEFV curve, were determined in 119 steroid-naïve individuals with atopic asthma aged 8 to 16 years, and in 92 age-matched healthy controls. Receiver operating characteristic (ROC) curve analyses were performed to determine the cutoff points of FeNO and angle ${\beta}$ that provided the best combination of sensitivity and specificity for asthma detection. Results: Asthmatic patients had a significantly smaller angle ${\beta}$ and higher FeNO compared with healthy controls (both, P<0.001). For asthma detection, the best cutoff values of angle ${\beta}$ and FeNO were observed at $189.3^{\circ}$ and 22 parts per billion, respectively. The area under the ROC curve for the combination of angle ${\beta}$ and FeNO improved to 0.91 (95% confidence interval [CI], 0.87-0.95) from 0.80 (95% CI, 0.75-0.86; P<0.001) for angle ${\beta}$ alone and 0.86 (95% CI, 0.82-0.91; P=0.002) for FeNO alone. In addition, the combination enhanced sensitivity with no significant decrease in specificity. Conclusion: These data suggest that the combined use of the curvilinearity of the MEFV curve and FeNO is a useful tool to differentiate between children with and without atopic asthma.

Aging Workforce and Organizational Innovation: Curvilinearity and the Moderating Role of Age Diversity (고령화와 조직 혁신: 비선형성과 연령 다양성의 조절효과)

  • Park, Jisung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.440-446
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    • 2018
  • This study examines the contrasting effects of an aging workforce on organizational innovation and the moderating role of age diversity. By utilizing a knowledge-based view, this study asserts that an aging workforce can contribute to organizational innovation to some degree due to accumulated firm-specific knowledge and experiences as well as various social networks within and outside the firm. On the contrary, as the portion of an aging workforce increases, the negative effect of the aging workforce on organizational innovation can overwhelm the positive effects because of the limitations of new knowledge creation. In addition, this study explores the effect of age diversity to moderate the relationship between aging workforce and organizational innovation.Empirical findings showed that an aging workforce and organizational innovation had an inverted-U relationship, and age diversity moderated this curvilinear relationship as this study predicted. These theoretical arguments and empirical findings highlight the necessity to explore the complex effects of an aging workforce on organizational innovation as well as additional factors influencing the relationship between aging workforce and firm innovation.

Conflict Management and Turnover Intention: Multi-level Curvilinearity and the Moderating Role of Trust in Leader (갈등관리와 이직의도: 다수준 비선형성과 리더신뢰의 조절효과)

  • Kim, Cheolyoung;Park, Jisung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.253-263
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    • 2018
  • This paper examined the U-shape curvilinear relationship between team level conflict management and individual level turnover intention by using exit-voice theory, bandwagon effect, and social loafing theory. In addition to the non-linear relationship between team-level conflict management and individual-level turnover intentions, we also examined how trust in leaders has a moderating effect on this relationship. The samples were collected from a South Korean manufacturing company with 331 team members from 48 teams and items were measured twice to avoid common method biases. The intercepts-as-outcomes model of hierarchical linear modelling was conducted to verify the hypothesis. Results supported the cross-level curvilinear hypothesis which indicated that employees' turnover intention sharply decreased if the activeness of group conflict management was small and increases slightly, but this tendency moderated as activeness increases. After passing the lowest point, their turnover intention increased in the end. However, the moderation effect of trust in leader on this relationship was not statistically significant and hypothesis 2 was rejected. This paper explained the effects of group dynamics of conflict management on individual turnover intention. Such evidence may elucidate the importance of managing the social loafing behavior on conflict management process. This paper examined the sequential, multi-level, and curvilinear relationship between conflict management and turnover intention. Organizations and managers will benefit from avoiding the human resource loss by managing the conflict management process.

A Study on application of Trapezoidal Steel Box Tunnelling Method (지중압입체를 이용한 지하구조물 축조방법의 적용성 연구)

  • Jun, Sung Bai
    • Journal of the Society of Disaster Information
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    • v.4 no.2
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    • pp.138-154
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    • 2008
  • The conventional non-dig underground structure building method which made an appearance to reduce the social and environmental costs and maximize the efficiency of the social overhead capital facilities could not help being uneconomical because of many problems such as unnecessary excessive excavation, water leakage, obstacle interference, difficulty of curvilinear application and connection complexity between propelled and injected bodies due to indiscriminate application of small and large circular steel pipes without consideration of the site conditions. The T.S.T.M, in which a protruded square tube is applied as a propulsion and injection body in a design that considered site conditions such as ground condition, depth of soil and live load, was able to be economical as it solved the problems of water resistance, minimization of obstacle interference and curvilinearity, and we can see that it can be applied to all grounds by utilizing or complementing the target ground in terms of engineering. Also in configuring the transverse section, it is possible to not only secure excellent structural safety but also implement all of the above engineering characteristics not only in the square cross section but also in the arch cross section, so it was possible to build structures on any section or ground, and we could confirm the LCC reduction effect and the VE effect.

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