• 제목/요약/키워드: sensitivity study

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Sensitivity analysis of melt spinning process by frequency response

  • Hyun, Jae-Chun;Jung, Hyun-Wook;Lee, Joo-Sung
    • Korea-Australia Rheology Journal
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    • 제14권2호
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    • pp.57-62
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    • 2002
  • The sensitivity of the final filament to the ongoing sinusoidal disturbances has been Investigated in the viscoelastic spinning using frequency response method. Amplification ratios or gains of the spinline cross-sectional area at the take-up to any disturbances show resonant peaks along the frequency regime, where the frequencies at theme points directly correspond to the imaginary parts of the successive leading eigenvalues from the linear stability analysis. As shown in Jung et al. (1999) and Lee et al (2001), the sensitivity results on the effect of various process conditions such as spinline cooling and fluid viscoelasticity, obtained by dynamic transient simulation have been corroborated in this study. That is, increasing spinline cooling makes the system less sensitive to disturbances, thus stabilizes the spinning. Also, an increasing viscoelasticity for extension-thickening fluids decreases the sensitivity of the spinning. i.e., stabilizing the system, where, as it increases the sensitivity of the spinning of extension-thinning fluids. Furthermore, it has been found in the present study that the inertia force as one of secondary forces causes the system to be more stabile or less sensitive to process disturbances.

마이크로 ESPI 기법에 의한 면내 변형 측정 민감도 향상 (Improvement of Sensitivity to In-plane Strain/Deformation Measurement by Micro-ESPI Technique)

  • 김동일;기창두;허용학
    • 한국정밀공학회지
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    • 제23권8호
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    • pp.54-63
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    • 2006
  • Enhancement methods of sensitivity to in-plane strain measurement by micro-ESPI(Electronic Speckle Pattern Interferometry) technique were proposed using TiN and Au thin films. Micro-tensile strain over the micro-tensile specimens, prepared in micro-scale by those films, was measured by micro-tensile loading system and micro-ESPI system developed in this study. The subsequent measurement of in-plane tensile strain in the micro-sized specimens was introduced using the micro-ESPI technique, and the micro-tensile stress-strain curves for these films were determined. To enhance the sensitivity to measurement of in-plane tensile strain, algorithms of the phase estimation by using curve fitting of inter-fringe and the discrete Fourier Transform with object-induced dynamic phase shifting were developed. Using these two algorithms, the micro-tensile strain-stress curves were generated. It is shown that the algorithms for enhancement of the sensitivity suggested in this study make the sensitivity to measurement of the in-plane tensile strain increase.

푸드 색채 감성에 관한 연구 (A Study on Sensitivity of Food Color)

  • 김지영;나정기
    • 한국식품영양학회지
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    • 제18권4호
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    • pp.385-394
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    • 2005
  • The objective of this study is to stimulate the satisfaction on food color sensitivity through objectifying the color sensitivities on customer's foods. The preference analysis on food sensitivity adjectives is measured on 5-point scale by preferring degree on each adjectives. And it is calculated on the sensitivities for the SD method that is used for finding whether it is strong or not on food image stimulus which was photographed on the 8 restaurants in Seoul. We found the outcome as follows. The most preferred sensitivity adjective is 'cleanness', and the worst preferred one is 'unshapliness'. It is differed on genders by $95\%$ confidence interval. The attractiveness, simplicity, richness, comfort and elegance are derived from the result of factor analysis for food color sensitivity. The yellow or orange color foods are main one for the simplicity and comfort. The orange color food are fit on richness and elegance factor, and it will be most effective if choosing the color more similar to brown one.

Multiple Chemical Sensitivity in Chemical Laboratory Workers

  • Perez-Crespo, Juan;Lobato-Canon, Rafael;Solanes-Puchol, Angel
    • Safety and Health at Work
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    • 제9권4호
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    • pp.473-478
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    • 2018
  • Background: Multiple Chemical Sensitivity (MCS) is an acquired disease which etiology remains unknown. It is characterized by the development of sensitivity to certain chemical products. Most of the hypotheses formulated to explain the syndrome associate it to a previous exposition to some kind of volatile chemical. University researchers in chemical laboratories suffer a phenomenon of multi-exposition to chemical agents at low concentration during long periods of time although in an irregular form. Many of these chemical agents have similar properties to those suspicious of causing MCS. This article studies the prevalence of MCS in laboratory researchers. Methods: The study group is university researchers in chemical laboratories. The control group was obtained from administrative personnel who work in the same universities and therefore, are not exposed to chemical products from the laboratories, but have the same exposition to the rest of environmental polluting agents from the area and from the buildings of the university. In this study, it is used the Quick Environmental Exposure and Sensitivity Inventory (QEESI) (sensitivity of 92%/specificity of 95%). Results: The results showed that the prevalence of MCS for the university researchers is not related to exposition by inhalation to multiple chemical agents, at low concentration. Conclusions: The results disagree with one of the main etiological hypotheses of MCS, which is based on the existence of hypersensitive people, who presents a response after prolonged expositions to very low concentrations during a long period of time.

어린이집에서의 인간관계가 직무몰입을 매개로 보육민감성에 미치는 영향 (The Influence of Human Relationships on Care Sensitivity Mediated by Work Immersion at Child Care Centers)

  • 김선희;이완정
    • 한국보육지원학회지
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    • 제16권6호
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    • pp.233-252
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    • 2020
  • Objective: The purpose of this study is to verify the effect of childcare teachers' positive human relationships in childcare centers on care sensitivity to children through their work immersion. Methods: The subjects of this study were child care teachers who were conveniently sampled from Incheon City. A total of 380 surveys were distributed, and a total of 334 surveys were analyzed, Poor or incomplete questionnaires collected were excluded. The. Sobel Test and Baron & Kenny's multi-regression were used for the analysis with the SPSS 23.0 program. Results: Child care teachers' positive relationships with directors, with their fellow teachers, and with parents had an influence on teachers' care sensitivity to children. Teacher's positive relationships with their fellow teachers and with parents had an influence on teachers' work immersion, which mediated the relationships between teacher's human relationship and their care sensitivity to children. Conclusion/Implications: The positive relationships of child care teachers directly and indirectly affect their sensitivity to children through teachers' work immersion.

초등학교 고학년 아동의 사회부과 완벽주의가 대인불안에 미치는 영향: 이분법적 사고와 거부민감성의 순차적 매개효과 (The Effect of Socially Prescribed Perfectionism in Upper Elementary School Students on Their Interpersonal Anxiety: The Sequential Mediating Effect of Dichotomous Thinking and Rejection Sensitivity)

  • 강영서;박주희
    • Human Ecology Research
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    • 제62권1호
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    • pp.165-179
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    • 2024
  • This study examined the effects of perceived discrimination on multicultural adolescents regarding feelings of This study examined the direct effect of socially prescribed perfectionism on interpersonal anxiety in upper elementary school students and the sequential mediating effect of dichotomous thinking and rejection sensitivity on this relationship. The sample comprised 306 upper elementary school students (grades 4 to 6; 149 boys, 48.7%) in Seoul, Incheon, and Busan. The Data were collected through an online self-report questionnaire completed by the participants and analyzed using SPSS version 27.0 and MPlus version 8.7 software. The analyses revealed three key findings. First the direct effect of socially prescribed perfectionism on interpersonal anxiety was not statistically significant. Second dichotomous thinking mediated the relationship between socially prescribed perfectionism and interpersonal anxiety, whereas rejection sensitivity did not. Finally, socially prescribed perfectionism influenced interpersonal anxiety through the sequential mediation of dichotomous thinking and rejection sensitivity. In conclusion, although socially prescribed perfectionism does not directly influence interpersonal anxiety, children may experience interpersonal anxiety in situations involving dichotomous thinking due to socially prescribed perfectionism, leading to rejection sensitivity. These findings suggest that interventions for interpersonal anxiety in upper elementary school students should focus on psychological problems attributed to socially prescribed perfectionism.

파라메트릭 횡동요 수치해석의 민감도 및 불확실성에 대한 연구 (Study on Numerical Sensitivity and Uncertainty in the Analysis of Parametric Roll)

  • 박동민;김태영;김용환
    • 대한조선학회논문집
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    • 제49권1호
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    • pp.60-67
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    • 2012
  • This study considers the numerical analysis on parametric roll for container ships. As a method of numerical simulation, an impulse-response-function approach is applied in time domain. A systematic study is carried out for the parametric roll of two container ships, particularly observing the sensitivity of computational results to some parameters which can affect the analysis of parametric roll. The parameters to be considered are metacentric height (GM), simulation time window, and the discretization of wave spectrum. Based on the result of parametric roll simulation, numerical sensitivity and uncertainty in computational analysis are discussed.

Empowering Intercultural Communicative Competence through Metacognitive Reading Strategy

  • Chang, Hyung-Ji
    • 영어어문교육
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    • 제18권2호
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    • pp.1-20
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    • 2012
  • This study aims to propose using English reading strategies to enhance Intercultural Communicative Competence (ICC) for EFL learners. The study recruited college-level participants who were enrolled in a general English reading course (N=30) and administrated the surveys with a Repeated Measures Design (RMD). In the survey, an intercultural sensitivity scale and metacognitive reading strategies inventory were conducted for comparison. During the instruction, participants were asked to use the R.I.D.E.R. (i.e. Read, Image, Describe, Evaluate, and Repeat) strategy for visualization of text, which is aimed at facilitating the use of metacognitive reading strategies. In the results, participants showed a statistically significant increase both in the intercultural sensitivity level and the use of metacognitive reading strategies after the practice of R.I.D.E.R for one semester. Further analysis was appended to the results by the correlation and regression analysis, and proposed that participants benefit their development of intercultural sensitivity from the use of metacognitive reading strategies. Therefore, the study suggests that implementing metacognitive reading strategies facilitates college EFL readers to increase their cultural sensitivity, which empowers ICC through English reading (176words).

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강체모드분리와 급수전개를 통한 고유치 문제에서의 준해석적 설계 민감도 개선에 관한 연구(II) -동적 문제 - (A Refined Semi-Analytic Sensitivity Study Based on the Mode Decomposition and Neumann Series Expansion in Eigenvalue Problem(II) - Eigenvalue Problem -)

  • 김현기;조맹효
    • 대한기계학회논문집A
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    • 제27권4호
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    • pp.593-600
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    • 2003
  • Structural optimization often requires the evaluation of design sensitivities. The Semi Analytic Method(SAM) fur computing sensitivity is popular in shape optimization because this method has several advantages. But when relatively large rigid body motions are identified for individual elements. the SAM shows severe inaccuracy. In this study, the improvement of design sensitivities corresponding to the rigid body mode is evaluated by exact differentiation of the rigid body modes. Moreover. the error of the SAM caused by numerical difference scheme is alleviated by using a series approximation for the sensitivity derivatives and considering the higher order terms. Finally the present study shows that the refined SAM including the iterative method improves the results of sensitivity analysis in dynamic problems.