• Structural Engineering and Mechanics
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• v.38 no.3
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• pp.283-300
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• 2011

A new conception of fundamental tasks in dynamics of the bridge-track-train systems (BTT), with the aim to evaluate moving load's models adequacy, has been developed. The 2D physical models of BTT systems, corresponding to the fundamental tasks, have been worked out taking into account one-way constraints between the moving unsprung masses and the track. A method for deriving the implicit equations of motion, governing vibrations of BTT systems' models, as well as algorithms for numerical integration of these equations, leading to the solutions of high accuracy and relatively short times of simulations, have been also developed. The derived equations and formulated algorithms constitute the basis for numerical simulation of vibrations of the considered systems.

• Structural Engineering and Mechanics
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• v.38 no.3
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• pp.301-314
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• 2011

The paper constitutes the second part of the author's study. The first part (Podworna 2010) formulates four fundamental tasks in dynamics of the bridge-track-train systems. The following cyclic moving loads are considered: a concentrated forces stream (model P), an unsprung masses stream (model M), a single-mass viscoelastic oscillators stream (model $M_o$) and a double-mass viscoelastic oscillators stream (model $MM_o$). Three problems precluding to the numerical simulations have been developed, i.e., prediction of the forced resonances, the parameters of integration of equations of motion, the output results. A computer programme was written in Pascal and numerical research in the scope of the fundamental tasks was worked out. The investigations were focused on adequacy evaluation of the moving load models, P, M, $M_o$, $MM_o$, in predicting dynamic processes in railway bridges.

• Research in Mathematical Education
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• v.5 no.2
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• pp.87-98
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• 2001

The Center for Science Gifted Education (CSGE) of Chongju National University of Education was established in 1998 with the financial support of the Korea. Science & Engineering Foundation (KOSEF). In fact, we had prepared mathematics and science gifted education program beginning in 1997. It was possible due to the commitment of faculty members with an interest in gifted education. Now we have 5 classes in Mathematics, two of which are fundamental, one of which is a strengthened second-grade class gifted elementary school students, and one a fundamental class, and one a strengthened class for gifted middle school students in Chungbuk province. Each class consists of 16 students selected by a rigorous examination and filtering process. Also we have a mentoring system for particularly gifted students in mathematics. We have a number of programs for Super-Saturday, Summer School, Winter School, and Mathematics and Science Gifted Camp. Each program is suitable for 90 or 180 minutes of class time. The types of tasks developed can be divided into experimental, group discussion, open-ended problem solving, and exposition and problem solving tasks. Levels of the tasks developed for talented elementary students in mathematics can be further divided into grade 5 and under, grade 6, and grade 7 and over. Types of the tasks developed can be divided into experimental, group discussion, open-ended problem solving, and exposition and problem solving task. Also levels of the tasks developed for talented elementary students in mathematics can be divided into the level of lower than grade 5, level of grade 6, and level of more than grade 7. Three tasks developed and practiced are reported in this article.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.223-228
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• 2010

This study investigated the closed quotient and other voice quality parameters using electroglottography (EGG) in sustaining the vowel /a/ and reading a sentence at the comfortable pitch and loudness in healthy Korean adults. Seventy two healthy adults (36 men, 36 women) aged 20~40 years were included in the study. The tasks were recorded and analyzed using Lx Speech Studio. In vowel sustaining task, closed quotient (Qx), fundamental frequency (Fx), sound pressure level (SPL), Jitter, and Shimmer were measured. In sentence reading task, closed quotient (DQx), fundamental frequency (DFx), and sound pressure level (DAx) were measured. The sex effects were observed on Qx, Fx, Shimmer, DQx, and DFx. Men had significantly higher Qx and DQx than women, but had significantly lower Shimmer than women. However, there was no sex effect on Jitter. The task effects on Qx and SPL as well as DQx and DAx were also assessed. Qx and SPL were significantly higher than DQx and DAx in both gender. This study showed that the closed quotients in both vowel sustaining and sentence reading tasks were significantly related to other voice quality parameters. Therefore, clinicians and researchers should describe the voice quality parameters like fundamental frequency, sound pressure level, Jitter, Shimmer, and so on when reporting closed quotients using EGG.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.164-166
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• 2012

In this paper, we proposed a method for extracting predominant melody of polyphonic music based on harmonic structure. Harmonic structure is an important feature parameter of monophonic signal that has spectral peaks at the integer multiples of its fundamental frequency. We extract all fundamental frequency candidates contained in the polyphonic signal by verifying the required condition of harmonic structure. Then, we combine those harmonic peaks corresponding to each extracted fundamental frequency and assign a rank to each after calculating its harmonic average energy. We run pitch tracking based on the rank of extracted fundamental frequency and continuity of fundamental frequency, and determine the predominant melody. For the query by singing/humming (QbSH) task, we proposed Dynamic Time Warping (DTW) based matching engine. Our system reduces false alarm by combining the distances of multiple DTW processes. To improve the performance, we introduced the asymmetric sense, pitch level compensation, and distance intransitiveness to DTW algorithm.

• Phonetics and Speech Sciences
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• v.15 no.4
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• pp.53-60
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• 2023

This study compared the absolute error of estimated fundamental frequency (AEF0) using voice - (VRP) and speech range profile (SRP) tasks across various etiological groups with voice disorders. Additionally, we explored the association between AEF0 and related voice parameters within each specific etiological group. The participants included 120 individuals, comprising 30 each from the functional (FUNC), organic (ORGAN), and eurological (NEUR) voice disorder groups, and a normal control group (NC). Each participant performed voice and SRP tasks, and the fundamental frequency of connected speech was measured using electroglottography (EGG). When comparing the AEF0 measures across the etiological groups, there were no differences in Grade and Severity among the patients. However, variations were observed in AEF0_VRP and AEF0_SUM. Specifically, AEF0_VRP was higher in the ORGAN group than in the FUNC and NC groups, whereas AEF0_SUM was higher in the ORGAN group than in the NC group. Furthermore, within FUNC and NEUR, AEF0 showed a positive correlation with Grade, while in ORGAN, it exhibited a positive correlation with the mean closed quotient (CQ). Attention should be paid to the application of AEF0 measures and related voice variables based on the etiological group. This study provides foundational information for the clinical application of AEF0 measures.

• Journal of Korean Public Health Nursing
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• v.32 no.3
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• pp.424-437
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• 2018

Purpose: This study was to conducted to search for factors influencing the confidence of core fundamental nursing skill performance (CC) based on comparative analysis, of the relationship between problem solving ability (PS), self-directed learning ability (SL) and CC of nursing students. Methods: This study was conducted based on questionnaires (208) given to senior nursing students. Data were analyzed by the t-test, ANNOVA and Scheffe's test. Moreover, Pearson's correlation coefficient and hierarchical regression were conducted to determine the relationship between items. Results: Proving Solving ability differed significantly in SC. In addition, satisfaction with core fundamental nursing skills (SL) differed significantly by gender, academic performance of last semester, support for nursing, and SC. Moreover, PS was found to have a normal relationship with SL and CC, and SL was found to have a normal relationship with CC. Conclusion: Education strategy should include methods of increasing the PS of student to improve CC in nursing education. Moreover, SL education should be used to increase nursing tasks and effective adaptation to their circumstances as a clinical nurse after graduation.

• Journal of Music and Human Behavior
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• v.12 no.2
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• pp.1-18
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• 2015

The purpose of this study was to compare the vocal characteristics of 40 adults with and without cerebral palsy (CP), upon presentation of three speech tasks (i.e., reading, chanting, and singing). The Praat program was utilized to generate data on fundamental frequency, voice intensity, jitter, and shimmer. The results of the analysis revealed no significant differences on fundamental frequency and intensity. However, both groups showed significant decreases in jitter and shimmer when engaged in singing tasks. The analysis of group differences indicated that adults with CP showed significantly higher variation scores on jitter and shimmer than the group without CP, and the difference on jitter and shimmer became greater during rhythmic chanting. In terms of jitter variation, the interaction effects according to the groups and types of speech tasks were greater, demonstrating the differences between the two groups. This study can be utilized as a basic research, regarding changes in vocal characteristics of adults with CP according to different musical speech tasks.

• School Mathematics
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• v.9 no.1
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• pp.45-64
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• 2007

The primary purposes of this study were to investigate how sixth graders would react to the types of tasks with regard to the comprehension of graphs and what differences might be among the kinds of graphs, and to raise issues about instructional methods of graphs. A descriptive study through pencil-and-paper tests was conducted. The tests consisted of 48 questions with 4 types of tasks (reading the data, reading between the data, reading beyond the data, and understanding the situations) and 6 kinds of graphs. The conclusions drawn from the results obtained in this study were as follows: First, it is necessary to foster the ability of interpreting the data and understanding the situation in graphs as well as that of reading the data and finding out the relationships in the data. Second, it is informative for teachers to know students' difficulties and thinking processes. Third, in order to develop understanding of graphs, it is important that students solve different types of tasks beyond simple question-answer tasks. Fourth, teachers need to pay attention to teach fundamental factors such as reading the data with regard to line graphs and stem-and-leaf plots Finally, graph type and task type interact to determine graph-comprehension performance. Therefore, both learning all kinds of graphs and being familiar with multiple types of tasks are important.

• Journal of Biomedical Engineering Research
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• v.43 no.6
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• pp.375-381
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• 2022

Brain-computer interface (BCI) is a technology that allows users with motor disturbance to control machines by brainwaves without a physical controller. Motor imagery (MI)-BCI is one of the popular BCI techniques, but it needs a long calibration time for users to perform a mental task that causes high fatigue to the users. MI is reported as showing a similar neural mechanism as motor execution (ME) and motor observation (MO). However, integrative investigations of these three tasks are rarely conducted. In this study, we propose a new paradigm that incorporates three tasks (MI, ME, and MO) and conducted a comparative analysis. For this study, we collected Electroencephalograms (EEG) of motor imagery/execution/observation from 28 healthy subjects and investigated alpha event-related (de)synchronization (ERD/ERS) and classification accuracy (left vs. right motor tasks). As result, we observed ERD and ERS in MI, MO and ME although the timing is different across tasks. In addition, the MI showed strong ERD on the contralateral hemisphere, while the MO showed strong ERD on the ipsilateral side. In the classification analysis using a Riemannian geometry-based classifier, we obtained classification accuracies as MO (66.34%), MI (60.06%) and ME (58.57%). We conclude that there are similarities and differences in fundamental neural mechanisms across the three motor tasks and that these results could be used to advance the current MI-BCI further by incorporating data from ME and MO.