• Steel and Composite Structures
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• v.20 no.6
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• pp.1345-1368
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• 2016

This paper presents the probabilistic-based assessment of composite steel-concrete structures through an innovative framework. This framework combines model identification and reliability assessment procedures. The paper starts by describing current structural assessment algorithms and the most relevant uncertainty sources. The developed model identification algorithm is then presented. During this procedure, the model parameters are automatically adjusted, so that the numerical results best fit the experimental data. Modelling and measurement errors are respectively incorporated in this algorithm. The reliability assessment procedure aims to assess the structure performance, considering randomness in model parameters. Since monitoring and characterization tests are common measures to control and acquire information about those parameters, a Bayesian inference procedure is incorporated to update the reliability assessment. The framework is then tested with a set of composite steel-concrete beams, which behavior is complex. The experimental tests, as well as the developed numerical model and the obtained results from the proposed framework, are respectively present.

• Journal of The Korean Association For Science Education
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• v.17 no.2
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• pp.201-207
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• 1997

This study was performed to survey the achievements in problem solving by the inquiring experiment, which was done by the superior group in the traditional cocepts-centered written tests. The purpose of this study was to identify characteristics of inquiring experimental assessment by analyzing differences between concepts-centered written and inquiring experimental tests. The subjects of this study was 211 applicants. They are the superior group of the 9th grade students, and score in the top 1% of total achievements percentage in school. They also have passed the primary entrance examination. The inquiring experimental test was developed according to the curriculum in school, and is composed of 5 subcategories: problem-perception and formulating hypothesis, designing an experiment, carring out an experiment, recording data and drawing conculsion, and generalizing conculsions and communicaton. The checklists of each subcategory were made and testing methods were divided into observation and report. The major results of this study are as follows: 1. The achievements in each subcategory of inquiring experimental performance were very low in the superior group who took the concepts-centered written tests. 2. The results of factor and correlation analyses in this study confirmed the abilities measured by inquiring experimental assessment differed from abilities measured by existing tests. These results indicated that even students who achieved high in scientific knowledge, these abilities were not automatically transformed inquiry process which many other abilities were integrated into. Therefore, problem solving ability requires integrated abilities which are fostered by inquiring experimental tasks. This suggests that new instrument for assessment must be developed to measure integrating ability especially where scientifically gifted students are selected, or where entrance examinations to the science schools are administered.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1616-1629
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• 2023

To quantify the conservatism of existing ASME strain-based evaluation methods for seismic loading, this paper presents very low cycle fatigue test data of elbows under various cyclic loading conditions and comparison of evaluation results with experimental failure cycles. For strain-based evaluation methods, the method presented in ASME BPVC CC N-900 and Sec. VIII are used. Predicted failure cycles are compared with experimental failure cycle to quantify the conservatism of evaluation methods. All methods give very conservative failure cycles. The CC N-900 method is the most conservative and prediction results are only ~0.5% of experimental data. For Sec. VIII method, the use of the option using code tensile properties gives ~3% of experimental data, and the use of the material-specific reduction of area can reduce conservatism but still gives ~15% of experimental data.

• Smart Structures and Systems
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• v.2 no.2
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• pp.127-140
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• 2006

In this study, a wavelet-based covariance-driven system identification technique is proposed for damage assessment of structures under ambient excitation. Assuming the ambient excitation to be a white-noise process, the covariance computation is shown to be able to separate the effect of random excitation from the response measurement. Wavelet transform (WT) is then used to convert the covariance response in the time domain to the WT magnitude plot in the time-scale plane. The wavelet coefficients along the curves where energy concentrated are extracted and used to estimate the modal properties of the structure. These modal property estimations lead to the calculation of the stiffness matrix when either the spectral density of the random loading or the mass matrix is given. The predicted stiffness matrix hence provides a direct assessment on the possible location and severity of damage which results in stiffness alteration. To demonstrate the proposed wavelet-based damage assessment technique, a numerical example on a 3 degree-of-freedom (DOF) system and an experimental study on a three-story building model, which are all under a broad-band excitation, are presented. Both numerical and experimental results illustrate that the proposed technique can provide an accurate assessment on the damage location. It is however noted that the assessment of damage severity is not as accurate, which might be due to the errors associated with the mode shape estimations as well as the assumption of proportional damping adopted in the formulation.

• Journal of Elementary Mathematics Education in Korea
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• v.24 no.3
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• pp.279-297
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• 2020

The purpose of this study is to find ways to establish and operate Process-focused Assessment in the classroom as the 2015 revised curriculum has emerged. As a way of doing so, we proposed a Process-focused Assessment through self-assessment and looked at the impact of the applied classes on the mathematical academic performance and affective domain of fifth-grade elementary school students. After selecting two classes of fifth grade with proven homogeneity for research, the experimental group applied Process-focused Assessment through self-assessment and the teacher-led Process-focused Assessment to the comparative group. As a result, it was confirmed that the classes applying Process-focused Assessment through self-assessment significantly improved the math and academic performance of fifth-grade elementary school students. The affective domain of the experimental group did not change significantly, but the analysis of the students' comments and interview data showed that they had more interest and confidence in mathematics.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.137-142
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• 2009

One of the most important aspects of conducting this microbial risk assessment (MRA) is determining the model in microbial behaviors in food systems. However, to fully these modeling, large expenditures or newly laboratory experiments will be spent to do it. To overcome these problems, it has to be considered to develop the new strategies that can be used data in the published literatures. This study is to show whether or not the data set from the published experimental data has more value for modeling for MRA. To illustrate this suggestion, as example of data set, 4 published Salmonella survival in Cheddar cheese reports were used. Finally, using the GInaFiT tool, survival was modeled by nonlinear polynomial regression model describing the effect of temperature on Weibull model parameters. This model used data in the literatures is useful in describing behavior of Salmonella during different time and temperature conditions of cheese ripening.

• English Language & Literature Teaching
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• no.5
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• pp.149-189
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• 1999

Assessment can be defined as any method used to understand the current knowledge that a student possesses. Assessment may influence decisions about grades, placement, instructional needs, and curriculum. Therefore, the purpose of assessment is to identify how the students think and know, to diagnose the difficulties they face, and to reflect the result of assessment on teaching. But the traditional multiple-choice test failed to evaluate and teach higher-level thinking and problem-solving skills. In this context, performance assessment is being required as an alternative assessment to get better understanding about what the students can do as well as what they know. This article points out some weaknesses of traditional assessments, and comments on the theoretical background and necessity of performance assessment. And it presents more specific information about performance assessment and some examples. It is certain that performance assessment is student-centered and future-oriented. But performance assessment can't be the surest and best way of evaluating the students' abilities. We are just on the way of another experimental stage for improving teaching methodology. More supplementary analyses and further improvements are needed.

• Korean Journal of Child Studies
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• v.30 no.5
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• pp.225-243
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• 2009

This study analyzed the effects of dynamic assessment in terms of scaffolding group types and young children's measurement ability levels. Participants were five-year-old children in Busan divided into 2 experimental groups and control groups. The Assessment Tools for Young Children's Measurement Ability (Ko & Hwang, 2008) consisted of 4 sub tests for ‘length', 'width', and 'weight' concepts. Data were analyzed by t-test and ANOVA. Results showed significant differences between experimental and control groups in post-test scores, but no significant differences between individual and peer collaboration groups in amount of scaffolding. Significant improvements showed in all of the measurement ability level groups : individual higher, individual lower, peer collaboration higher and peer collaboration lower level scaffolding groups.

• Earthquakes and Structures
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• v.15 no.6
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• pp.595-603
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• 2018

Shake table testing has been regarded as one of the most effective experimental approaches to evaluate seismic response of structural systems subjected to earthquakes. However, reproducing a prescribed acceleration time history precisely over the frequency of interest is challenging because shake table test systems are eventually nonlinear by nature. In addition, interaction between the table and specimen could affect the control accuracy of shake table testing significantly. Various novel control algorithms have been proposed to improve the control accuracy of shake table testing; however, reference values for control performance assessment remain rare. In this study, reference values for control performance assessment of shake table testing are specified based on the statistical analyses of 1,209 experimental data provided by the Seismic Simulator Laboratory of National Center for Research on Earthquake Engineering in Taiwan. Three individual reference values are considered for the assessment including the root-mean-square error of the achieved acceleration time history; the percentage of the spectral acceleration that exceeds the determined tolerance range over the frequency of interest; and the error-ratio of the achieved peak ground acceleration. Quartiles of the real experimental data in terms of the three objective variables are obtained, providing users with solid and simple references to evaluate the control performance of shake table testing. Finally, a set of experimental data of a newly developed control framework implementation for uni-axial shake tables are used as an application example to demonstrate the significant improvement of control accuracy according to the reference values provided in this study.

• Child Health Nursing Research
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• v.22 no.2
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• pp.117-125
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• 2016

Purpose: This study was done to examine the effect of direct practice of newborn health assessment on nursing student's clinical competence and self-efficacy and to propose effective strategies for clinical education on newborn care. Methods: Design was a nonequivalent control group quasi-experimental study. The direct practice program was composed of a lecture, demonstration, drill and feedback using a manikin, and repeated direct practice regarding newborn health assessment. Participants were 65 student nurses taking the pediatric nursing practicum in the nursery room at M hospital. The experimental group (n=33) participated in the direct practice program for newborn health assessment and the control group (n=32) received the traditional practice method. Nursing clinical competence was assessed by two nurse investigators and structured questionnaires were used to measure self-efficacy. Results: The experimental group's clinical competence was significantly higher than that of the control group (t=-4.82, p=.000). However no significant difference was found between the two groups for self-efficacy (t=1.264, p=.211). Conclusion: These findings indicate that the direct practice program is effective in improving nursing student's clinical competence, but it was not effective in increasing self-efficacy. Direct practice in various clinical education settings is recommended and longitudinal effects be evaluated.