• Title/Summary/Keyword: Adaptation to Uncertainty

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An Exploratory Study of Factors affecting on Adaptation to Uncertainty in Rheumatoid Arthritis Patients (류마티스 관절염 환자의 불확실성에 대한 적응에 영향을 미치는 요인 탐색)

  • Yoo, Kyung-Hee
    • Journal of muscle and joint health
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    • v.8 no.2
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    • pp.230-249
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    • 2001
  • This study was conducted to investigate the affecting factors on the adaptation to uncertainty in patients having rheumatoid arthritis. Subjects of the study constituted 222 patients who visited outpatient of rheumatic center in Seoul. Self report questionnaires were used to measure the variables affecting the adaptation to uncertainty. The variables affecting the adaptation to uncertainty were uncertainty, mastery, appraisal of danger, appraisal of opportunity, emotion focused coping, problem focused coping, pain, depression and activity of daily life(ADL). Reliability coefficients of these instruments were found Cronbach's $Alpha\;=\;.70{\sim}.94$. In data analysis, SPSSWIN 10.0 program was utilized for descriptive statistics, Pearson's correlation, and multiple regression analysis. The results were as follows. 1) The range of total pain scores was from 0 to 147 and the mean score of the pain in rheumatoid arthritis patients was 72.64. 2) The range of total depression scores was from 20 to 72 and the mean score of the depression in rheumatoid arthritis patients was 39.86. 3) The range of total ADL scores was from 22 to 80 and the mean score of the ADL in rheumatoid arthritis patients was 72.56. 4) Among the independent variables, significant factors to explain the adaptation to pain in patients were danger appraisal of uncertainty(p<.05) and emotion focused coping(p<.05). 5) Among the independent variables, significant factors to explain the adaptation to depression in patients were danger appraisal of uncertainty(p<.001), opportunity appraisal of uncertainty(p<.001) and mastery(p<.005). 6) Among the independent variables, significant factors to explain the adaptation to ADL in patients were mastery(p<.001) and danger appraisal of uncertainty(p<.05).

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A study on the Novel Sliding Mode Controller with Uncertainty Adaptation (불확실성 추정을 갖는 새로운 슬라이딩 모드제어기의 설계)

  • 김민찬;박승규;안호균;정은태
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.332-332
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    • 2000
  • In this paper, a novel sliding mode control with uncertainty adaptation is produced by introducing a virtual state. Because upper bounds of the uncertainty is difficult to know, we estimate these upper bound by using the simple adaptation law and design the novel sliding mode controller. The nominal controller is used the optimal controller to minimize cost function.

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Sliding Mode Control with Uncertainty Adaptation for Uncertain Input-Delay Systems (시간지연 시스템에서의 불확실성 추정을 갖는 슬라이딩 모드제어)

  • Roh, Young-Hoon;Oh, Jun-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.11
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    • pp.963-967
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    • 2000
  • This paper deals with a sliding mode control with uncertainty adaptation for the robust stabilization of input-delay systems with unknown uncertainties. A sliding surface including a state predictor is employed to compensate for the effect of the input delay. The proposed method does not need a priori knowledge of upper bounds on the norm of uncertainties, but estimates those upper bounds by adaptation laws based on the sliding surface. Then, a robust control law with the uncertainty adaptation is derived to ensure the existence of the sliding mode. A numerical example is given to illustrate the design procedure.

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Design of Sliding Mode Controller with Uncertainty Adaptation

  • Kim, Min-Chan;Nam, Jing-Rak;Park, Seung-Kyu;Kwak, Gun-Pyong
    • Journal of information and communication convergence engineering
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    • v.4 no.3
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    • pp.118-122
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    • 2006
  • In this paper, a sliding mode control method with uncertainty adaptation is proposed by introducing the virtual state. Because upper bound of the uncertainty is very difficult to know, we estimate this by using the simple adaptation law and design the sliding surface which has dynamic of nominal system. An optimal controller is used by nominal controller. And if initial values of the virtual state are chosen properly, the reaching phase is removed.

An output feedback control based on the adaptatation law for the estimation of the bound of the uncertainty (Uncertainty의 경계치 추정기법을 기초로 한 출력궤환제어)

  • Yoo, Dong-Sang;Choi, Han-Ho;Chung, Myung-Jin
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.687-690
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    • 1991
  • In deterministic design of feedback controllers for uncertain dynamical systems, the bound on the uncertainty is an important clue to guarantee the asymptotic stability or uniform ultimate boundedness of the closed-loop system. In this paper, using only the measurable output we propose an adaptation law for the estimation of the bound of the uncertainty. And based on this adaptation law an adaptive control which renders the uncertain dynamical systems uniformly ultimately bounded is constructed.

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An explanatory model of quality of life in high-risk pregnant women in Korea: a structural equation model

  • Mihyeon Park;Sukhee Ahn
    • Women's Health Nursing
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    • v.29 no.4
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    • pp.302-316
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    • 2023
  • Purpose: This study aimed to develop and validate a structural model for the quality of life (QoL) among high-risk pregnant women, based on Roy's adaptation model. Methods: This cross-sectional study collected data from 333 first-time mothers diagnosed with a high-risk pregnancy in two obstetrics and gynecology clinics in Cheonan, Korea, or participating in an online community, between October 20, 2021 and February 20, 2022. Structured questionnaires measured QoL, contextual stimuli (uncertainty), coping (adaptive or maladaptive), and adaptation mode (fatigue, state anxiety, antenatal depression, maternal identity, and marital adjustment). Results: The mean age of the respondents was 35.29±3.72 years, ranging from 26 to 45 years. The most common high-risk pregnancy diagnosis was gestational diabetes (26.1%). followed by preterm labor (21.6%). QoL was higher than average (18.63±3.80). Above-moderate mean scores were obtained for all domains (psychological/baby, 19.03; socioeconomic, 19.00; relational/spouse-partner, 20.99; relational/family-friends, 19.18; and health and functioning, 16.18). The final model explained 51% of variance in QoL in high-risk pregnant women, with acceptable overall model fit. Adaptation mode (β=-.81, p=.034) and maladaptive coping (β=.46 p=.043) directly affected QoL, and uncertainty (β=-. 21, p=.004), adaptive coping (β=.36 p=.026), and maladaptive coping (β=-.56 p=.023) indirectly affected QoL. Conclusion: It is essential to develop nursing interventions aimed at enhancing appropriate coping strategies to improve QoL in high-risk pregnant women. By reinforcing adaptive coping strategies and mitigating maladaptive coping, these interventions can contribute to better maternal and fetal outcomes and improve the overall well-being of high-risk pregnant women.

The Influence of Uncertainty and Social Support on General Well-being among Hemodialysis Patients (혈액투석 환자가 지각하는 불확실성과 사회적 지지가 안녕감에 미치는 영향)

  • Kim, Youn-Jin;Choi, Hee-Jung
    • The Korean Journal of Rehabilitation Nursing
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    • v.15 no.1
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    • pp.20-29
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    • 2012
  • Purpose: The purpose of this study was to explore factors affecting uncertainty and general well-being based on Uncertainty in Illness Theory. Methods: Data were collected from 125 outpatients who had received hemodialysis. The path model among four concepts, such as period of hemodialysis, social support, uncertainty, and general well-being, was tested. Tangible support, positive social interaction, affectionate, and emotional/informational support were measured as social support. Adaptation in the model was operationalized as general well-being which consisted of anxiety, depression, positive well-being, self-control, and general health. Results: All paths were statistically significant at the level of ${\alpha}$=.05. The significant paths were the path from period of hemodialysis to uncertainty (t=-2.86), social support to uncertainty (t=-2.01), uncertainty to general wellbeing (t=-2.85), and social support to general well-being (t=3.55). Conclusion: Patients who perceived low uncertainty and high social support were likely to feel well-being. Therefore, nurses should give patients appropriate information according to their needs and have meaningful interaction with patients to reduce their uncertainty and render social support.

Uncertainty, Depression, and Ways of Coping in Women with Endometriosis (자궁내막증 여성의 불확실성, 우울 및 대처방식)

  • Suh, Youngseong;Ahn, Sukhee
    • Korean Journal of Adult Nursing
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    • v.17 no.5
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    • pp.743-752
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    • 2005
  • Purpose: The purposes of this study were to identify the level of total symptom distress, uncertainty, depression and ways of coping in women with endometriosis based on Mishel's model of Uncertainty in Chronic illness, and to exam the relationships among symptom distress, depression and ways of coping and the mediating effect of ways of coping between uncertainty and depression. Method: The research was used for correlational research design and data were collected with 123 women with endometriosis who live in a local area by convenience sampling. Results: The finding showed that the levels of symptom distress and uncertainty were moderate and the depression was above the middle level. There were positive relationships among symptom distress, uncertainty and depression but a negative relationship between problem focused coping and depression. The significant predictors for depression were symptom distress, uncertainty, and problem focused coping with 40% of explained variance. Problem focused coping showed mediating effect between uncertainty and depression. Conclusion: Therefore, nursing intervention for the strategy of increasing problem focused coping as well as lowering uncertainty and depression is recommended. Further study is needed to conduct a repetitive study with randomized nationwide population and to evaluate the theory with different outcomes for adaptation versus maladaptation.

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Robust Control of Nonlinear Systems with Adaptive Fuzzy System (적응 퍼지 시스템을 이용한 비선형 시스템의 강인 제어)

  • 구근모;왕보현
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1996.10a
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    • pp.158-161
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    • 1996
  • A robust adaptive tracking control architecture is proposed for a class of continuous-time nonlinear dynamic systems for which an explicit linear parameterization of the uncertainty in the dynamics is either unknown or impossible. The architecture employs an adaptive fuzzy system to compensate for the uncertainty of the plant. In order to improve the robustness under approximation errors and disturbances, the proposed architecture includes deadzone in adaptation laws. Unlike the previously proposed schemes, the magnitude of approximate errors and disturbances is not required in the determination of the deadzone size, since it is estimated using the adaptation law. The proposed algorithm is proven to be globally stable in the Lyapunov sense, with tracking errors converging to the proposed architecture.

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A Study on the Renegotiation and Adaptation of International Long Term Commercial Contracts: Focusing on the Contracts without the Renegotiating Clauses (국제장기상거래계약에서의 재협상 및 계약변경에 관한 연구: 원계약 상 관련 조항이 포함되지 않은 계약을 중심으로)

  • Joo‐Young Yoon
    • Korea Trade Review
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    • v.45 no.5
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    • pp.117-139
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    • 2020
  • In case of international long-term transactions, there are various risks of economic change of circumstances including skyrocketing price increase and shortage of raw material, as well as force majeure in a general sense. Nevertheless, pretty many of international long-term commercial contracts do not include the provisions of renegotiation and adaptation of the contract. In this case, possibility of renegotiation and adaptation depends mainly on the applicable law. Namely, it may be possible or not, according to choice of law. The reason is that national laws have nuances each other, and most of national courts are traditionally reluctant to accept hardship. and also, provisions of international uniform law (CISG) has ambiguity and inflexibility in relation to the problems of change of circumstances. Accordingly, this paper analyzes comparatively the doctrines and provisions related to renegotiation and adaptation of contracts of the most representative countries such as England, U.S.A., France, Germany as well as provisions CISG and soft law such as PICC. By doing so, the author makes clear which laws of instruments is more flexible or acceptable in allowing renegotiation and adaptation of long-term commercial contracts, and emphasizes on the importance of inclusion of express terms by using other alternative supplementing clauses, as a best solution for settling the problems of legal uncertainty of contract in relation to renegotiation and adaptation.