• Title/Summary/Keyword: Sensitivity coefficient

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Analysis of the dynamic characteristics for the change of design parameters of an underwater vehicle using sensitivity analysis

  • Jeon, Myungjun;Yoon, Hyeon Kyu;Hwang, Junho;Cho, Hyeon Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.4
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    • pp.508-519
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    • 2018
  • In order to design the hull form of an underwater vehicle in the conceptual design phase, the dynamic characteristics depending on the hull form parameters should be identified. Course-keeping stability, turning ability, yaw-checking ability, and mission competence are set to be the indices of the dynamic characteristics, and the geometric parameters for the bare hull and rudder are set to be the hull form design parameters. The total sensitivity of the dynamic characteristics with respect to the hull form parameters is calculated by the chain rule of the partial sensitivity of the dynamic characteristics with respect to the hydrodynamic coefficients, and the partial sensitivity of the hydrodynamic coefficients with respect to the hull form parameters. Based on the sensitivity analysis, important hull form parameters are selected, and those optimal values to satisfy the required intercept time of mission competence of a specific underwater vehicle and turning rate are estimated.

Application of sensitivity analyses in premixed combustion within a porous ceramic burner (다공 세라믹 연소기 속에서의 예혼합연소에 대한 민감도 해석의 적용)

  • Im, In-Gwon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.2
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    • pp.162-172
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    • 1998
  • A numerical study of premixed combustion within a porous ceramic burner (PCB) is performed to understand flame behavior with respect to various model parameters. Basic flame structure within the porous ceramic burner and species profiles such as NO and CO are examined. Sensitivity analysis of flame speed, gas and solid temperature, NO and CO emission from the burner with respect to reaction steps and various physical properties of the ceramic material is applied to find the most significant parameters in selection of porous materials for the porous ceramic burner. Effects of thermal conductivity, extinction coefficient and scattering albedo on the burner characteristics are studied through the sensitivity analysis. The results of sensitivity study reveal the order of importance in ceramic material properties to get suitable burner performance. Scattering albedo, which governs the ratio of absorbed energy by the ceramic material to total radiative energy transferred, is one of the most important parameters in the material properties since it affects the actual absorbed radiation rate and thus it largely affects the flame structure. Through the study, it is found that the sensitivity study can be used to estimate the flame behavior within the porous ceramic burner more effectively.

The Effects of the Gender Sensitivity, the Gender Role Conflict on Nursing Professionalism in Nursing Students (간호대학생의 성인지 감수성, 성역할 갈등이 간호전문직관에 미치는 영향)

  • Woo, Chung-Hee;Yoo, Seung-Yeon
    • The Journal of Korean Society for School & Community Health Education
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    • v.22 no.3
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    • pp.41-54
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    • 2021
  • Objectives: This study aimed to confirm the degree of gender sensitivity, gender role conflict, nursing professionalism of nursing students and the factors that affect nursing professionalism. Methods: During Jan. 19 to Feb. 5 in 2021, the structured questionnaire was used for 187 nursing students by on-line research methods. Data were analyzed by descriptive analysis, mean comparison(t-test, ANOVA), correlation analysis(Pearson's correlation coefficient) and multiple regression using SPSS/WIN 25.0. Results: The gender sensitivity had positive relationship with nursing professionalism, and gender role conflict had negative relationship with nursing professionalism. And the prediction factors influencing nursing professionalism were major satisfaction, gender sensitivity and gender role conflict. The total variance was 8.2% by predictors. Conclusions: In order to improve the nursing professionalism of nursing students, various ways to increase the satisfaction level of major should be sought, and program should be prepared to improve gender sensitivity and reduce gender role conflict.

Mediating effect of moral sensitivity on the relationship between nursing professionalism and ethical decision-making confidence in nursing students (간호대학생의 간호전문직관과 윤리적 의사결정 자신감의 관계에서 도덕적 민감성의 매개효과)

  • Kang, Bae-Hwa;Cho, Hye-Young
    • The Journal of Korean Academic Society of Nursing Education
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    • v.29 no.2
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    • pp.180-189
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    • 2023
  • Purpose: The purpose of this study is to confirm the relationship between nursing students' nursing professionalism and ethical decision-making confidence, and to clarify the mediating effect of moral sensitivity which has a mutual influence on nursing professionalism and ethical decision-making confidence. Methods: The data collection for this study was conducted from January 23 to February 1, 2021 with junior and senior nursing students enrolled in five nursing departments in two regions. The data collected in this study were analyzed using the IBM SPSS statistics version 23.0 program. Results: Through this study, it was found that nursing professionalism (β=.47) and moral sensitivity (β=.32) acted as important influencing factors on the ethical decision-making confidence of nursing students, with an explanatory power of 31.2%. In addition, it was confirmed that there was a partial mediating effect of moral sensitivity in the relationship between the nursing professionalism and ethical decision-making confidence of nursing students, and the mediating effect coefficient of moral sensitivity was .16. Conclusion: Based on the results of the study, it is suggested to prepare a plan to increase ethical decision-making confidence and moral sensitivity when planning interventions to improve nursing professionalism in nursing students.

The Fabrication of Chromiun Thin-Film Strain Gauges and Its Characteristics (크롬박막 스트레인 게이지의 제작과 그 특성)

  • 김정훈;정귀상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.343-346
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    • 1997
  • This paper presents the basic characteristics of Cr thin-film, which were deposited on glass by DC magnetron sputtering. The optimized deposition condition of Cr thin-film strain gauges were input power 7w/cm$^2$and the Ar working pressure was 9mtorr. GF(Gauge Factor), TCR(Temperature Coefficient of Resistance) and TCS(Temperature Coefficient of Sensitivity) of Cr thin-film strain gauges were 5.86, 400 ppm/$^{\circ}C$ and 0 ppm/$^{\circ}C$, respectively.

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Uncertainty and Sensitivity Analysis of Time-Dependent Deformation in Prestressed Concrete Box Girder Bridges (프리스트레스트 콘크리트 박스 거더 교량의 시간에 따른 변형의 확률 해석 및 민감도 해석)

  • 오병환;양인환
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.149-159
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    • 1998
  • The reasonable prediction of time-dependent deformation of prestressed concrete(PSC) box girder bridges is very important for accurate construction as well as good serviceability. The long-term behavior is mostly influenced by the probabilistic characteristic of creep and shrinkage. This paper presents a method of statistical analysis and sensitivity analysis of creep and shrinkage effects in PSC box been taken into account - model uncertainty, parameter variation and environmental condition. The statistical and sensitivity analyses are performed by using the numerical simulation of Latin Hypercube sampling. For each sample, the time-dependent structural analysis is performed to produce response data, which are then statistically analyzed. The probabilistic prediction of the confidence limits on long-term effects of creep and shrinkage is then expressed. Three measure are examined to quantify the sensitivity of the outputs of each of the input variables. These are rank correlation coefficient(RCC), partical rank correlation coefficient(PRCC) and standardiozed rank regression coefficient(SRRC) computed on the ranks of the observations. Three creep and shrinkage models - i. e., ACI model. CEB-FIP model and the model in Korea Highway Bridge Specification - are studied. The creep model uncertainy factor and the relative humidity appear to be the most dominant factors with regard to the model output uncertainty.

A Study on the Parameters of WASP5 Model in Daechung Reservoir (대청호에서 WASP5 모델 매개변수에 관한 연구)

  • Han, Woon Woo;Kim, Kyu-Hyung;Ahn, Tae-Bong
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.3
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    • pp.69-77
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    • 2003
  • This study was carried out to evaluate the WASP5 model parameters and to analyze the sensitivity of parameters in Daechung Reservoir. The values predicted by the model and tendency were very similar to the observed data at Daejeon intake, so it is possible to predict water quality of the Daejeon intake region in the future. Results from the sensitivity analysis showed that Chlorophyll-a was sensitive to variations in saturated growth rate of phytoplankton, endogenous respiration rate of phytoplankton, extinction coefficient and temperature. T-N was sensitive to mineralization rate of dissolved organic nitrogen and temperature. T-P was affected by T-P load, temperature, extinction coefficient, mineralization rate of dissolved organic phosphorus and saturated growth rate of phytoplankton. BOD was influenced by deoxygenation rate and temperature, and DO was influenced by temperature. Adequate input data was applied and assessed through the model sensitivity analysis. So it is possible to distinguish the input data which need careful attention when it has application to model.

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Specification optimization and sensitivity analysis of Si3N4/SiO2 slot and ridge-slot optical waveguides for integrated-optical biochemical sensors (집적광학 바이오케미컬 센서에 적합한 Si3N4/SiO2 슬롯 및 릿지-슬롯 광 도파로 제원 최적화 및 감지도 해석)

  • Jang, Jaesik;Jung, Hongsik
    • Journal of Sensor Science and Technology
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    • v.30 no.3
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    • pp.139-147
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    • 2021
  • Numerical analysis was performed using FIMMWAVE to optimize the specifications of Si3N4/SiO2 slot and ridge-slot optical waveguides based on confinement factor and effective mode area. The optimized specifications were confirmed based on sensitivity in terms of the refractive index of the analyte. The specifications of the slot optical waveguide, i.e., the width of the slot and the width and height of the rails, were optimized to 0.2 ㎛, 0.46 ㎛, and 0.5 ㎛ respectively. When the wavelength was 1.55 ㎛ and the refractive index of the slot was 1.3, the confinement factor and effective mode area of 0.2024 and 2.04 ㎛2, respectively, were obtained based on the optimized specifications. The thickness of the ridge and the refractive index of the slot were set to 0.04 ㎛ and 1.1, respectively, to optimize the ridge-slot optical waveguide, and the confinement factor and effective mode area were calculated as 0.1393 and 2.90 ㎛2, respectively. When the confinement coefficient and detection degree of the two structures were compared in the range of 1 to 1.3 of the analyte index, it was observed that the confinement coefficient and sensitivity were higher in the ridge-slot optical waveguide in the region with a refractive index less than 1.133, but the reverse situation occurred in the other region. Therefore, in the implementation of the integrated optical biochemical sensor, it is possible to propose a selection criterion for the two parameters depending on the value of the refractive index of the analyte.

Effects of Nursing Students' Knowledge, Awareness and Moral sensitivity of standard precautions on Performance of standard precautions (간호대학생의 표준주의 지침에 대한 지식, 인지도 및 도덕적 민감성이 표준주의 지침 수행에 미치는 영향)

  • Jang, Hee-jung;Mo, Moon-hee
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.4
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    • pp.441-448
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    • 2021
  • The purpose of this study were to investigate knowledge, awareness, and moral sensitivity, performance of standard precaution, and to identify influencing factors on performance of standard precaution of nursing students. The subjects of this study were completed by 201 nursing students from 2 colleges in D City. Data were collected from December 2 to 20, 2019. Data were analyzed using the t-test, the ANOVA, the Pearson correlation coefficient, and multiple regression analysis by SPSS ver. 21.0. There were significant positive correlations among knowledge of standard precaution, awareness of standard precaution, and moral sensitivity on performance of standard precaution. The factors influencing performance of standard precaution of the study subjects were awareness of standard precaution(β=.78, p<.001), and the explanatory power of these variables was 60.5%. The development of awareness of standard precaution education program that focuses awareness of standard precaution change is needed.

Research on Temperature Sensing Characteristics of Fiber Bragg Grating in Wide Temperature Range

  • Naikui Ren;Hongyang Li;Nan Huo;Shanlong Guo;Jinhong Li
    • Current Optics and Photonics
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    • v.8 no.2
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    • pp.162-169
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    • 2024
  • This study investigates the temperature sensitivities of fiber Bragg grating (FBG) across a broad temperature spectrum ranging from -196 ℃ to 900 ℃. We developed the FBG temperature measurement system using a high-temperature tubular furnace and liquid nitrogen to supply consistent high and low temperatures, respectively. Our research showed that the FBG temperature sensitivity changed from 1.55 to 10.61 pm/℃ in the range from -196 ℃ to 25 ℃ when the FBG was packaged with a quartz capillary. In the 25-900 ℃ range, the sensitivity varied from 11.26 to 16.62 pm/℃. Contrary to traditional knowledge, the FBG temperature sensitivity was not constant. This inconsistency primarily stems from the nonlinear shifts in the thermo-optic coefficient and thermal expansion coefficient across this temperature spectrum. The theoretically predicted and experimentally determined temperature sensitivities of FBGs encased in quartz capillary were remarkably consistent. The greatest discrepancy, observed at 25 ℃, was approximately 1.3 pm/℃. Furthermore, it was observed that at 900 ℃, the FBG was rapidly thermally erased, exhibiting variable reflected intensity over time. This study focuses on the advancement of precise temperature measurement techniques in environments that experience wide temperature fluctuations, and has considerable potential application value.