• Title/Summary/Keyword: predictive validity

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Anti-slosh effect of a horizontal porous baffle in a swaying/rolling rectangular tank: Analytical and experimental approaches

  • George, Arun;Cho, Il-Hyoung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.833-847
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    • 2021
  • The horizontal porous baffle and its effect as an anti-slosh device have been investigated intensively in a swaying and rolling rectangular tank. To accurately assess the level at which porous baffles reduce liquid sloshing, the Matched Eigenfunction Expansion Method (MEEM) has been utilized as an analytical tool. The velocity potentials in the horizontal baffle-covered fluid region are expressed by the sum of the homogeneous and particular solutions to avoid solving the complex dispersion equation. By applying an equivalent linearized quadratic loss model, the nonlinear algebraic equation is derived and solved by implementing the Newton-Raphson iterative scheme. To prove the validity of the present theoretical model, a series of experiments have been conducted with different centered horizontal porous baffles with varying porosities and submerged depths in a swaying and rolling rectangular tank. Reasonably good agreements are obtained regarding the analytical solutions and the experiment's findings. The influence of porosity, submerged depth, and length of a centered horizontal porous baffle on anti-slosh performance have been analyzed, especially at resonance modes. The developed predictive tool can potentially provide guidelines for optimal design of the horizontal porous baffle.

Using Predictive Analytics to Profile Potential Adopters of Autonomous Vehicles

  • Lee, Eun-Ju;Zafarzon, Nordirov;Zhang, Jing
    • Asia Marketing Journal
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    • v.20 no.2
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    • pp.65-83
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    • 2018
  • Technological advances are bringing autonomous vehicles to the ever-evolving transportation system. Anticipating adoption of these technologies by users is essential to vehicle manufacturers for making more precise production and marketing strategies. The research investigates regulatory focus and consumer innovativeness with consumers' adoption of autonomous vehicles (AVs) and to consumers' subsequent willingness to pay for AVs. An online questionnaire was fielded to confirm predictions, and regression analysis was conducted to verify the model's validity. The results show that a promotion focus does not have a significantly positive effect on the automation level at which consumers will adopt AVs, but a prevention focus has a significantly positive effect on conditional AV adoption. Consumer innovativeness, consumers' novelty-seeking have a significantly positive relationship with high and full AV adoption, and consumers' independent decision-making has a significantly positive effect on full AV adoption. The higher the level of automation at which a consumer adopts AVs, the higher the willingness to pay for them. Finally, using a neural network and decision tree analyses, we show methods with which to describe three categories for potential adopters of AVs.

The effects of stress mindset on perceived stress and self-control in college students (대학생의 스트레스 마인드셋과 자기통제의 관계에서 지각된 스트레스의 매개효과)

  • Koo, Minju;Shin, Yeoul;Park, Daeun
    • Korean Journal of School Psychology
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    • v.16 no.3
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    • pp.265-281
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    • 2019
  • This study, for the first time, examined predictive validity of stress mindset-the beliefs about the effects of stress-on perceived stress and self-control in college students. To do so, 159 college students completed self-reported questionnaires on stress mindset, perceived stress, and self-control. The results indicated that compared to students who believed stress can be utilized, those who believed stress is strictly harmful tended to experience higher level of stress, which, in turn, predicted lower self-control. These findings suggest that changing college students ' stress mindset may be a good way to help them to thrive mentally and behaviorally.

Uncertainty Quantification of Model Parameters Using Reflood Experiments and TRACE Code (재관수 실증실험과 TRACE 코드를 활용한 모델 변수의 불확실도 정량화)

  • Seon Oh Yu;Kyung Won Lee
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.20 no.1
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    • pp.32-38
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    • 2024
  • The best estimate plus uncertainty methodologies for loss-of-coolant accident analyses make use of the best-estimate codes and relevant experimental databases. Inherently, best-estimate codes have various uncertainties in the model parameters, which can be quantified by the dedicated experimental database. Therefore, this study was devoted to establishing procedures for identifying the input parameters of predictive models and quantifying their uncertainty ranges. The rod bundle heat transfer experiments were employed as a representative reflood separate effect test, and the TRACE code was utilized as a best-estimate code. In accordance with the present procedure for uncertainty quantification, the integrated list of the influential input parameters and their uncertainty ranges was obtained through local sensitivity calculations and screening criteria. The validity of the procedure was confirmed by applying it to uncertainty analyses, which checks whether the measured data are within computed ranges of the variables of interest. The uncertainty quantification procedure proposed in this study is anticipated to provide comprehensive guidance for the conduct of uncertainty analyses.

Validation on Adult Fall Assessment Tools: Focusing on Hospitalized Patients in a General Hospital (낙상위험 사정도구의 타당도 비교: 일개 종합병원의 입원 환자를 중심으로)

  • Kim, Hayng Suk;Choi, Eun Hee
    • Journal of muscle and joint health
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    • v.31 no.2
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    • pp.65-74
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    • 2024
  • Purpose: This study was conducted to verify fall predictive power and reasonable fall risk assessment tool by a comparative analysis of the sensitivity, specificity, positive forecast and negative forecast of each tool by applying Morse Fall Scale (MFS), Johns Hopkins Fall Risk Assessment Tool (JHFRAT), and Fall Assessment Scale-Korean version (FAS-K) through electronic medical records to adult patients hospitalized in a general hospital in Korea. Methods: We performed a retrospective evaluation study from January to December 2018, 123 fall groups experiencing falls during hospitalization and 123 non-falls groups were selected. Data presented a reasonable assessment tool that predicts and distinguishes fall high-risk patients through area comparison based on the ROC curve for each tool. Results: In the ROC curve analysis by fall risk assessment group, the AUC of MFS is shown to be .706 (good), JHFRAT is shown to be .649 (sufficient) and FAS-K is shown to be .804 (very good). FAS-K at a cut-off score of 4, sensitivity, specificity, and positive and negative prediction values were 83.7%, 60.2%, 67.8%, and 78.7%, respectively. Conclusion: Based on the above findings, it is believed that the FAS-K was presented as a suitable and reasonable tool for predicting falls for adult patients in general hospitals.

The ages and stages questionnaire: screening for developmental delay in the setting of a pediatric outpatient clinic (ASQ :소아과외래에서의 발달지연 선별검사)

  • Kim, Eun Young;Sung, In Kyung
    • Clinical and Experimental Pediatrics
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    • v.50 no.11
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    • pp.1061-1066
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    • 2007
  • Purpose : Early identification of developmental disabilities allows intervention at the earliest possible point to improve the developmental potential. The Ages and Stages Questionnaire (ASQ), a parent- completed questionnaire, can be used as a substitute for formal screening tests. The purpose of this study was to evaluate the validity of the Korean version of the ASQ (K-ASQ) as a screening tool for detecting developmental delay of young Korean children in the setting of a busy pediatric outpatient clinic. Methods : Parents completed the K-ASQ in the waiting room of the pediatric outpatient clinic of St. Mary's Hospital, Catholic University Medical College. Out of 150 completed the ASQ, 67 who were born term and had no previous diagnosis of developmental delay, congenital anomalies, or neurological abnormalities were enrolled. The cut-off values of less than 2 standard deviations (SD) below the mean for the ASQ were used to define a "fail", and children who failed in one or more domains tested were classified as "screen-positive". Diagnosis of developmental delay was made when the developmental indices fell below -1 SD of the Bayley Scales of Infant Development-II. Results : (1) The mean age of children was $16.4{\pm}7.4$ months. Ten children (14.9%) were small-for- gestational age infants. The mean birth weight and gestational age were $3.1{\pm}0.6kg$ and $38.8{\pm}1.4$ weeks. Nine children (13.4%) were twins and 33 (49.0%) were male. The mean maternal education in years was $13.6{\pm}2.4$, and 31.3% had full-time jobs. The time for completing the ASQ was $10.2{\pm}3.0$ minutes. (2) Seventeen children (25.4%) were classified as screen-positive, four of them were delayed in development. Among eight children diagnosed with developmental delay, four were screen-positive and the other four were screen-negative by the ASQ. (3) The test characteristics of the ASQ were as follows: sensitivity (50.0%); specificity (78.0%); positive predictive value (23.5%); negative predictive value (92.0%). Conclusion : The high negative predictive value of the K-ASQ supports its use as a screening tool for developmental delay in the setting of a pediatric outpatient clinic.

Development of a Prediction Model for Advertising Effects of Celebrity Models using Big data Analysis (빅데이터 분석을 통한 유명인 모델의 광고효과 예측 모형 개발)

  • Kim, Yuna;Han, Sangpil
    • Journal of the Korea Convergence Society
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    • v.11 no.8
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    • pp.99-106
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    • 2020
  • The purpose of this study is to find out whether image similarity between celebrities and brands on social network service be a determinant to predict advertising effectiveness. To this end, an advertising effect prediction model for celebrity endorsed advertising was created and its validity was verified through a machine learning method which is a big data analysis technique. Firstly, the celebrity-brand image similarity, which was used as an independent variable, was quantified by the association network theory with social big data, and secondly a multiple regression model which used data representing advertising effects as a dependent variable was repeatedly conducted to generate an advertising effect prediction model. The accuracy of the prediction model was decided by comparing the prediction results with the survey outcomes. As for a result, it was proved that the validity of the predictive modeling of advertising effects was secured since the classification accuracy of 75%, which is a criterion for judging validity, was shown. This study suggested a new methodological alternative and direction for big data-based modeling research through celebrity-brand image similarity structure based on social network theory, and effect prediction modeling by machine learning.

Parasellar Extension Grades and Surgical Extent in Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenomas : A Single Surgeon's Consecutive Series with the Aspects of Reliability and Clinical Validity

  • Lee, Sang-Hyo;Park, Jae-Sung;Lee, Song;Kim, Sung-Won;Hong, Yong-Kil
    • Journal of Korean Neurosurgical Society
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    • v.59 no.6
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    • pp.577-583
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    • 2016
  • Objective : The inter-rater reliability of the modified Knosp's classification was measured before the analysis. The clinical validity of the parasellar extension grading system was evaluated by investigating the extents of resection and complication rates among the grades in the endoscopic endonasal transsphenoidal surgery (EETS) for pituitary adenomas. Methods : From November 2008 to August 2015, of the 286 patients who underwent EETS by the senior author, 208 were pituitary adenoma cases (146 non-functioning pituitary adenomas, 10 adrenocorticotropic hormone-secreting adenomas, 31 growth hormone-secreting adenomas, 17 prolactin-secreting adenomas, and 4 thyroid-stimulating hormone-secreting adenomas; 23 microadenomas, 174 macroadenomas, and 11 giant adenomas). Two neurosurgeons and a neuroradiologist independently measured the degree of parasellar extension on the preoperative sellar MRI according to the modified Knosp's classification. Inter-rater reliability was statistically assessed by measuring the intraclass correlation coefficient. The extents of resection were evaluated by comparison of the pre- and post-operative MR images; the neurovascular complications were assessed by reviewing the patients' medical records. The extent of resection was measured in each parasellar extension grade; thereafter, their statistical differences were calculated. Results : The intraclass correlation coefficient value of reliability across the three raters amounted to 0.862. The gross total removal (GTR) rates achieved in each grade were 70.0, 69.8, 62.9, 21.4, 37.5, and 4.3% in Grades 0, 1, 2, 3A, 3B, and 4, respectively. A significant difference in the extent of resection was observed only between Grades 2 and 3A. In addition, significantly higher complication rates were observed in the groups above Grade 3A. Conclusion : Although the modified Knosp's classification system appears to be complex, its inter-rater reliability proves to be excellent. Regarding the clinical validity of the parasellar extension grading system, Grades 3A, 3B, and 4 have a negative predictive value for the GTR rate, with higher complication rates.

The Development of Physical Functioning Scale for Community-Dwelling Older Persons (지역사회 노인의 신체기능 평가도구 개발)

  • Lee, Kyung-Jong;Han, Geun-Shik;Yoon, Soo-Jin;Lee, Yeon-Kyung;Kim, Chan-Ho;Kim, Jeong-Lim;Lee, Yun-Hwan
    • Journal of Preventive Medicine and Public Health
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    • v.35 no.4
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    • pp.359-374
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    • 2002
  • Objectives : To develop a physical functioning instrument for older adults living in the community. Methods : A representative sample of 979 people aged 65 years or over were interviewed in-person. Of these, 199 people also completed a detailed in-hospital examination. The scale items were selected based on the frequency of endorsement, along with the item-total and inter-item correlations. The associations of the scale with their physical performance and clinical examination were analyzed to evaluate the criterion-related validity. Construct validity was assessed using factor analysis, and internal consistency through Cronbach's alpha and item-total correlations. Test-retest reliability was measured by agreement between the household survey and the repeat survey at the in-hospital examination. Results : Initially, 23 items on the level of difficulty, ranging from no difficulty to an inability to complete a task, with the specific mobility and self-care tasks were included. Those with a high frequency of endorsement and a low inter-item or item-total correlations were excluded, resulting in a 10-item Physical Functioning (PT) scale. Equal weights were given to each item and a summated score was calculated. Significant associations were found between the PF scores and the physical performance, surrey and clinical data. The scale revealed a 2-factor (mobility and self-care) structure. Cronbach's alpha was 0.92 and the item-total correlations were in the 0.63 to 0.78 range. Pearson's correlations for the test-retest ranged between 0.56 and 0.61. Conclusions : The newly developed Physical Functioning (PF) scale showed good psychometric properties in older people. Further work, however, is needed to improve its sensitivity to discriminate higher levels of functioning, in addition to assessing its predictive value in detecting changes in health.

Development and Validation of the Vicarious Trauma Scale for Sexual Violence Counselor (성폭력 상담자 대리외상 척도 개발 및 타당화)

  • Heo, Chan-hee;Lee, Jee-yon
    • The Journal of the Korea Contents Association
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    • v.20 no.12
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    • pp.393-405
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    • 2020
  • The purpose of this study is to develop and validate a scale of vicarious trauma for sexual violence counselors. To this end, the concept of composition and preliminary questions of the vicarious trauma of sexual violence counselors were selected through the analysis of a content of individual interviews of sexual violence counselors and the precedent theory. Then, preliminary scale was developed after expert's evaluation of the validity of the contents. Next, as a result of a confirmatory factor analysis on the preliminary scale of 349 sexual violence counselors with experience in consulting sexual violence clients, it is confirmed that the conformity of five-factor structure was found to be favorable. As a result of convergent and discriminative validity analysis, it was confirmed that the developed scale is a reasonable tool for measuring vicarious trauma of sexual violence counselors by showing proper correlation with Secondary Traumatic Stress Scale, Counselor Burnout Inventory and Inventory of Countertransference Behavior. Furthermore, as a result of correlation analysis between professional identity and Belief in a Just World, it confirmed that it has predictive validity of the scale by indicating a high negative correlation. Furthermore, the relationship between the scale of vicarious trauma of sexual violence counselors and career background was analyzed. Finally, based on the results of this study, the significance and limitations of this study and the direction of future research were discussed.