• Title/Summary/Keyword: Model-based test

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Factors related to the short-term and long-term intentions of healthy eating among Chinese adults living in Shanghai and parts of Anhui Province of China using the theory of planned behavior (계획적 행동이론 기반 상하이 및 안후이성 거주 중국 성인의 건강한 식행동의 장단기 의도와 관련된 요인)

  • Liu, Ani;Lee, Seungwoo;Hwang, Ji-Yun
    • Journal of Nutrition and Health
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    • v.55 no.1
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    • pp.188-199
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    • 2022
  • Purpose: This study investigated the relationship between 3 major constructs of the theory of planned behavior (TPB), i.e., attitude, subjective norms and perceived behavioral control (PBC) and past experience of healthy eating and intentions of healthy eating in the short-term and long-term in adults living in Shanghai and parts of Anhui Province, China. Methods: The online study questionnaire for this cross-sectional study was based on previously validated items. A total of 408 Chinese adults (aged 18-64 years) residing in Shanghai and parts of Anhui Province, China were included to examine relationships between 3 major constructs of TPB and past experience of healthy eating, and short-term and long-term intentions of healthy eating. Multiple linear regression model adjusted for age and body mass index (BMI) was employed to test relationships. Results: Only PBC among 3 major constructs of TPB was significantly related to short-term (p < 0.001) and long-term (p = 0.002) intention of healthy eating after adjustment for age and BMI. Past experience of healthy eating was more significantly related to long-term intention (p < 0.001) compared to short-term (p = 0.020) intention of healthy eating. The short-term and long-term intention models explained 70.5% and 48.8% of the variance, respectively. Conclusion: PBC is a potential determinant of both short-term and long-term behavioral intention of healthy eating regardless of past experience of healthy eating in adults residing in Shanghai and parts of Anhui Province, China. Our results indicate that programs promoting healthy eating to Chinese adults incorporate PCB to perform healthy eating under his or her control.

Multiple damage detection of maglev rail joints using time-frequency spectrogram and convolutional neural network

  • Wang, Su-Mei;Jiang, Gao-Feng;Ni, Yi-Qing;Lu, Yang;Lin, Guo-Bin;Pan, Hong-Liang;Xu, Jun-Qi;Hao, Shuo
    • Smart Structures and Systems
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    • v.29 no.4
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    • pp.625-640
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    • 2022
  • Maglev rail joints are vital components serving as connections between the adjacent F-type rail sections in maglev guideway. Damage to maglev rail joints such as bolt looseness may result in rough suspension gap fluctuation, failure of suspension control, and even sudden clash between the electromagnets and F-type rail. The condition monitoring of maglev rail joints is therefore highly desirable to maintain safe operation of maglev. In this connection, an online damage detection approach based on three-dimensional (3D) convolutional neural network (CNN) and time-frequency characterization is developed for simultaneous detection of multiple damage of maglev rail joints in this paper. The training and testing data used for condition evaluation of maglev rail joints consist of two months of acceleration recordings, which were acquired in-situ from different rail joints by an integrated online monitoring system during a maglev train running on a test line. Short-time Fourier transform (STFT) method is applied to transform the raw monitoring data into time-frequency spectrograms (TFS). Three CNN architectures, i.e., small-sized CNN (S-CNN), middle-sized CNN (M-CNN), and large-sized CNN (L-CNN), are configured for trial calculation and the M-CNN model with excellent prediction accuracy and high computational efficiency is finally optioned for multiple damage detection of maglev rail joints. Results show that the rail joints in three different conditions (bolt-looseness-caused rail step, misalignment-caused lateral dislocation, and normal condition) are successfully identified by the proposed approach, even when using data collected from rail joints from which no data were used in the CNN training. The capability of the proposed method is further examined by using the data collected after the loosed bolts have been replaced. In addition, by comparison with the results of CNN using frequency spectrum and traditional neural network using TFS, the proposed TFS-CNN framework is proven more accurate and robust for multiple damage detection of maglev rail joints.

Characteristics of Academic Hatred Explained by Self-Determination Motivation: A Study of High School Seniors (자기결정성 동기에 따른 학업반감 특성에 관한 연구: 고등학교 3학년 학생들을 대상으로)

  • Lee, Minyoung;Lee, Sangeun;Lee, Sang Min
    • Korean Journal of School Psychology
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    • v.17 no.3
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    • pp.379-399
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    • 2020
  • This study examined the relative influence of the five factors of the self-determination motivation on academic hatred. A total of 938 high school seniors (female 535, 57.0%) across eight schools in Seoul, Incheon, and Gyeonggi province were surveyed a month before Soo-neng (College Scholastic Ability Test). The findings of correlation analyses and hierarchical multiple regression analyses were summarized as follows. Academic hatred showed significant correlations with all the self-determination motivation factors except for introjected regulation. For hierarchical multiple regression analyses, starting with amotivation, the motivation factors indicating low level of self-determination were entered in order. In the final model, amotivation and introjected regulation had positive influence on academic hatred, and intrinsic regulation had negative influence on academic hatred. Specifically, introjected regulation which had no significant effect on academic hatred with amotivation and external regulation showed significant effect after identified regulation was added. Identified regulation lost its significant influence after intrinsic regulation was included. This study was meaningful in that it was the first study to clarify motivational characteristics of academic hatred based on self-determination theory. The study also presented its limitations, implications for school counseling intervention, and directions for future research.

Investigation on relative contribution of flow noise sources of ship propulsion system (선박 추진시스템 유동 소음원 상대적 기여도 분석)

  • Ha, Junbeom;Ku, Garam;Cheong, Cheolung;Seol, Hanshin;Jeong, Hongseok;Jung, Minseok
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.3
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    • pp.268-277
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    • 2022
  • In this study, each component of flow noise source of underwater propeller installed to the scale model of the KVLCC2 is investigated and the effect of each noise source on underwater-radiated noise is quantitatively analyzed. The computation domain is set to be the same as the test section of the large cavitation tunnel in the Korea Research Institute of Ship and Ocean Engineering. First, for the high-resolution computation of flow field which is noise source region, the incompressible multiphase Delayed Detached Eddy Simulation is performed. Based on flow simulation results, the Ffowcs Williams and Hawkings integral equation is used to predict underwater-radiated noise and its validity is confirmed through the comparison with the tunnel experiment result. For the quantitative comparison on the contribution of each noise source, the spectral levels of sound pressure and power levels predicted using propeller tip-vortex cavitation, blade surface and rudder surface as the integral region of noise sources are investigated. It is confirmed that the cavitation which is monopole noise source significantly contributed to the underwater-radiated noise than propeller blades and rudder which is dipole noise source, and the rudder have more contribution than propeller blades due to the influence of the propeller wake.

RANS simulation of secondary flows in a low pressure turbine cascade: Influence of inlet boundary layer profile

  • Michele, Errante;Andrea, Ferrero;Francesco, Larocca
    • Advances in aircraft and spacecraft science
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    • v.9 no.5
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    • pp.415-431
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    • 2022
  • Secondary flows have a huge impact on losses generation in modern low pressure gas turbines (LPTs). At design point, the interaction of the blade profile with the end-wall boundary layer is responsible for up to 40% of total losses. Therefore, predicting accurately the end-wall flow field in a LPT is extremely important in the industrial design phase. Since the inlet boundary layer profile is one of the factors which most affects the evolution of secondary flows, the first main objective of the present work is to investigate the impact of two different inlet conditions on the end-wall flow field of the T106A, a well known LPT cascade. The first condition, labeled in the paper as C1, is represented by uniform conditions at the inlet plane and the second, C2, by a flow characterized by a defined inlet boundary layer profile. The code used for the simulations is based on the Discontinuous Galerkin (DG) formulation and solves the Reynolds-averaged Navier-Stokes (RANS) equations coupled with the Spalart Allmaras turbulence model. Secondly, this work aims at estimating the influence of viscosity and turbulence on the T106A end-wall flow field. In order to do so, RANS results are compared with those obtained from an inviscid simulation with a prescribed inlet total pressure profile, which mimics a boundary layer. A comparison between C1 and C2 results highlights an influence of secondary flows on the flow field up to a significant distance from the end-wall. In particular, the C2 end-wall flow field appears to be characterized by greater over turning and under turning angles and higher total pressure losses. Furthermore, the C2 simulated flow field shows good agreement with experimental and numerical data available in literature. The C2 and inviscid Euler computed flow fields, although globally comparable, present evident differences. The cascade passage simulated with inviscid flow is mainly dominated by a single large and homogeneous vortex structure, less stretched in the spanwise direction and closer to the end-wall than vortical structures computed by compressible flow simulation. It is reasonable, then, asserting that for the chosen test case a great part of the secondary flows details is strongly dependent on viscous phenomena and turbulence.

Assessment of diet quality of adults from North Korea: using nutrition quotient (NQ) for Korean adults (북한이탈주민의 식사의 질 평가: 성인 영양지수를 기반으로)

  • SaeByeol Kwon;Kyoung-Nam Kim;Moon-Kyung Shin
    • Journal of Nutrition and Health
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    • v.56 no.2
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    • pp.217-230
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    • 2023
  • Purpose: The purpose of this study was to assess the diet intake status and quality of adults from North Korea who had lived in Seoul and Gyeonggi-do, using the nutrition quotient (NQ) for Korean adults. Methods: A number of 166 adults aged from 20 to 64 years were enrolled as study subjects. A structured questionnaire was used to collect information on their demographic characteristics, food consumption frequency, eating behaviors, and NQ. The NQ score was then used to measure the overall diet quality. The NQ score was composed of four major age-based categories. 'Balance', 'Diversity', 'Moderation', and 'Dietary behavior' were utilized as scores for measurements within each of the four categories. The scores for all four categories were summed up, resulting in the total NQ score. Participants' age groups were stratified by 20's, 30's, 40', and over 50's. A χ2 test and generalized linear regression (GLM) model were used to assess a significance for difference of subject distribution in categorical and continuous variables in the food consumption frequency, eating behaviors, and NQ scores. Results: Participants in younger age groups were more likely to report consumption of ramyeon, fast food, sweet and greasy baked products, processed beverage, delivery food, and night snacks than the older age groups. Most importantly, participants in 20's age group were less likely to report the total NQ and moderation score than the 50's age group. Conclusion: In this study, the 20's age group displayed a lower NQ characteristic for an unbalanced diet. Therefore, it is imperative for adults from North Korea to be given individualized diet instructions along with nutritional education programs.

The Effects of Group Coaching Program on Improving Metacognition Learning Ability for Adult Learners (성인학습자 대상 메타인지 학습능력 증진 그룹코칭 프로그램의 효과성 검증)

  • Hyunjin Kim;Taehee Kim
    • The Korean Journal of Coaching Psychology
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    • v.7 no.2
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    • pp.47-74
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    • 2023
  • The purpose of this study was to test the effectiveness of a group coaching program to promote metacognitive learning ability in an academic context for adult learners enrolled at a distance university. The topics and objectives of the group coaching program focused on understanding and applying the elements of 'metacognitive knowledge', and each session was conducted online by integrating 'planing-monitoring-regulating', an element of 'metacognitive regulation', into the REGROW model of coaching. To verify the effectiveness of the program, research participants were recruited from adult university students enrolled in A Cyber University and assigned to the experimental and control groups. The experimental group was given the program, while the control group was given the program after the completion of the study. Metacognitive learning ability level and academic self-efficacy were tested before and after the program for both groups, and a satisfaction survey was conducted for the experimental group. Analyses of the data revealed that the experimental group showed higher scores on both the overall and sub-scales of perceived metacognitive learning ability and academic self-efficacy compared to the control group. Participants in the experimental group also reported high satisfaction with the program, increased knowledge of metacognition, awareness and application of metacognitive strategies, and found the group coaching approach beneficial. Based on these findings, implications, and suggestions for future research are presented.

Statistical Techniques to Detect Sensor Drifts (센서드리프트 판별을 위한 통계적 탐지기술 고찰)

  • Seo, In-Yong;Shin, Ho-Cheol;Park, Moon-Ghu;Kim, Seong-Jun
    • Journal of the Korea Society for Simulation
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    • v.18 no.3
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    • pp.103-112
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    • 2009
  • In a nuclear power plant (NPP), periodic sensor calibrations are required to assure sensors are operating correctly. However, only a few faulty sensors are found to be calibrated. For the safe operation of an NPP and the reduction of unnecessary calibration, on-line calibration monitoring is needed. In this paper, principal component-based Auto-Associative support vector regression (PCSVR) was proposed for the sensor signal validation of the NPP. It utilizes the attractive merits of principal component analysis (PCA) for extracting predominant feature vectors and AASVR because it easily represents complicated processes that are difficult to model with analytical and mechanistic models. With the use of real plant startup data from the Kori Nuclear Power Plant Unit 3, SVR hyperparameters were optimized by the response surface methodology (RSM). Moreover the statistical techniques are integrated with PCSVR for the failure detection. The residuals between the estimated signals and the measured signals are tested by the Shewhart Control Chart, Exponentially Weighted Moving Average (EWMA), Cumulative Sum (CUSUM) and generalized likelihood ratio test (GLRT) to detect whether the sensors are failed or not. This study shows the GLRT can be a candidate for the detection of sensor drift.

Effects of Health-Related Food Labeling on Quality Assessment Before Purchase, Attitudes towards Using and Purchasing Products, and Purchase Intentions Based on the Theory of Planned Behavior (건강관련 식품표시가 구매 전 품질평가와 제품 사용 및 구매태도, 구매의도에 미치는 영향: 계획적 행동이론을 바탕으로)

  • Jun, Sangmin
    • Journal of Consumption Culture
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    • v.15 no.3
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    • pp.67-90
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    • 2012
  • When consumers choose healthy foods, they base their buying decisions on health-related food labeling and quality assessment of taste, health, and price. Moreover, both purchase experience and opinions of family and friends affect consumer choices. Focusing on these points, this study examined the effects of health-related food labeling on consumer choices by adding two variables-quality assessment of taste, health, and price and purchase experience-to the model of the theory of planned behavior. We also used structural equation modeling to test our hypotheses. In the study, health-related food labeling includes organic labeling, nutrient claims, and food additive labeling. We conducted a mail survey among 300 married women who buy cheese slices for their children more than once a month. It was discovered that health-related food labeling positively affected the level of quality assessment of taste, health, and price, and consequently led to positive attitudes and purchase intentions. Particularly, health-related food labeling positively influenced attitude toward using products without assessing the quality of taste, health, and price. The level of quality assessment of price positively affected attitude toward using and purchasing products, and purchase experience positively affected attitude toward using and purchasing products, and purchase intentions. The relationship between attitude to purchasing products and purchase intentions was the most positive, and the relationship between perceived behavioral control and purchase intentions was not significant. Overall, this study essentially contributes to the development of a theoretical framework of food labeling and consumer choices, which includes quality assessment of taste, health, and price and purchase experience, by using the theory of planned behavior.

Calculation of Bearing Capacity of Tapered Drilled Shafts in Cohesionless Soils Using Shape Factor (형상계수를 이용한 사질토 지반에 타설된 테이퍼말뚝의 지지력 산정)

  • Paik, Kyu-Ho;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.24 no.12
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    • pp.13-22
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    • 2008
  • Fourteen calibration ehamber tests were performed using one cylindrical and two tapered piles with different taper angles to investigate the changes of the bearing capacity of tapered piles with soil state and taper angle of piles. The results of calibration chamber tests show that the ultimate base resistance of tapered piles increases with increasing mean stress and relative density of soil. It also increases with increasing taper angle for medium sand, but with decreasing taper angle for dense sand. The ultimate shaft resistance of tapered piles increases as vertical and horizontal stresses, relative density and taper angle increase. Based on the results of model pile load tests, a new design method with shape factors for estimation of the bearing capacity of tapered piles is proposed considering the effect of soil state and taper angle on bearing capacity of tapered piles. In order to check the accuracy of predictions calculated using the new method, middle-scale field pile load tests were also conducted on cylindrical and tapered drilled shafts in clayey sand. Comparison of calculated values with measured ones shows that the new design method produces satisfactory predictions tor tapered piles.