• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1C
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• pp.63-74
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• 2008

Site response analyses were performed based on equivalent linear technique using the local geologic and dynamic site characteristics, which include soil profiles, shear wave velocity profiles and depth to bedrock for 125 sites collected in Korean Peninsula. From the results of site response analyses, 2-parameters site classification system based on the combination of mean shear wave velocity of soil and depth to bedrock was newly recommended for regions of shallow bedrock depth in Korea. First, as the borders of bedrock depth (H) for site classification were determined as 10m and 20m, the soil sites were divided into 3 classes as $H_1$, $H_2$ and $H_3$ sites. And then, the 3 site classes were subdivided into 7 classes based on the mean shear wave velocity of soil ($V_{s,soil}$). The feasibility of new site classification system was verified and the representative site coefficients ($F_a$ and $F_v$) and design response spectrum were suggested by analyzing uniform trend and dispersion of site coefficients for each site class. The suggested site coefficients and the regression curves present the nonlinear characteristics of soils according to the change of rock outcrop acceleration with uniform trend effectively. From the comparison between the mean values of response spectrum which was acquired from the site response analysis and the suggested design response spectrum, there was a little difference in some of site classes and it was verified to adjust the integration interval to make it more suitable for the site condition in Korea.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.413-418
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• 2019

Studies are now actively underway to confirm the degree of treatment and rehabilitation of patients with brain-related diseases (dementia, schizophrenia, depression, Parkinson's disease). Among them, Transcranial magnetic stimulation (TMS) is widely used in treatment because it is a technique that is used for noninvasive brain neuron control in patients with brain disorders. It can be seen that muscle fatigue of normal people increases during Transcranial magnetic stimulation. Therefore, in this paper, our purpose is to build an EMG measurement system to measure motor neuron-induced response during transcranial magnetic stimulation and We identify a motor-neutral response system using tendency in the RMS graph. As an experimental method, the Raw Data received through the surface EMG device and analyzed by RMS technique, after the contraction and relaxation movement of the biceps brachii. As a result of the experiment, we confirmed the trend of rising RMS graph, and it will can be used to determine the self-stimulation intensity for each individual in consideration of the data of the motor-neutral response.

• Journal of The Korean Association For Science Education
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• v.27 no.4
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• pp.354-365
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• 2007

The purpose of this study was to understand the undergraduate students' response characteristics by their cognitive conflict levels and result predictions when they were confronted with the learning tasks of action & reaction and electric circuits. The 147 engineering college students who were enrolled at the introductory physics classes were selected as the subjects for this study. The students were grouped by cognitive levels and result predictions. First, in action and reaction task, the trend of suspecting experimental results and finding the reasons was dominant; however, in electric circuits, the trend of accepting the results was dominant. Second, the reasons for the responses on the subcategories of cognitive conflict were different by the level of cognitive conflict. The responses were influenced by students' preexisting knowledge, former experiences, learning habits, learning motivation, and epistemological beliefs, etc. The high conflict group recognized what they do not consider and was positive to reappraise their preconceptions, while the low conflict group showed the tendency of accepting the situation without doubt and low interest on learning physics. In conclusion, students responses showed differences in cognitive conflict levels, result predictions and presented conflict tasks. The research results, especially the response characteristics, suggest that more research on effective cognitive conflict strategies appropriate for different tasks and students' conflicts are necessary for effective physics teaching.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.224-231
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• 2019

The current paper was conducted to unravel the influence of affect induction as a background emotion in the process of cognitive task to judge the degree of sequence in groups with or without anxiety symptoms. Four types of affect induction and two sequential task types were used as within-subject variables, and two types of college students groups classified under the Beck Anxiety Inventory (BAI) as a between-subject variable were selected to determine reaction times involving sequential judgment among the lexical relevance information. DmDx5 was used to present a series of stimuli and elicit a response from subjects. Repeated measured ANOVA analyses revealed that reaction times and error rates were significantly larger with anxiety participants compared to the normal group regardless of affect and task types. Within-subject variable effects found that specific affect type (sorrow condition) and number-related task type showed a more rapid response compared to other affect types and magnitude-related task type, respectively. In sum, these findings confirmed the difference in tendency with reaction time and error rates that varied as a function of accompanying affect types as well as anxiety level and task types suggesting the that underlying background affect plays a major role in processing affect-cognitive association tasks.

• Journal of the Korean Society for information Management
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• v.28 no.3
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• pp.335-353
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• 2011

This study examines how and which direction respondents who participated in 5-point Likert scale surveys change their initial responses when they are given an identical second survey after certain treatments. The research employs three identical questionnaires (first, second and third surveys) to analyze survey results based on group differences, kinds of treatment, survey purposes, and response change direction and the degree. This paper concludes that, first, it is significant that specialist groups do not change their initial responses compared to a general librarian group. Second, there are no differences by survey purpose; however, participants tend to change their initial responses by others' opinions rather than by previous use experiences. Third, participants who initially answered positively tend not to change their responses, and most participants who answered negatively change their initial responses in a positive direction. Fourth, when there are changes, participants change their initial responses by less than two points, and most of them change by one point. Finally, the hypothesis that middle responses change most and that participants who respond at both ends do not change their opinion was rejected by the finding that participants who answered on the negative end tend to change their initial responses in a positive direction.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.33-42
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• 2004

While transforming the inelastic system into the equivalent elastic one gives an advantage of simpler analysis, the actual inelastic behavior of the system is hardly modeled in the capacity spectrum method (CSM). Therefore, the accuracy of CSM depends on the precise estimation of equivalent period and damping ratio as well as the modification of the elastic response spectrum and the corresponding demand spectrum. In this paper, the effect of demand spectrums on the accuracy of CSM is evaluated. First, the response reduction factors provided in ATC-40 and Euro Code are evaluated. Numerical analysis results indicated that the acceleration responses obtained using the factor of Euro Code are closer to the actual response than those obtained using the factors of ATC-40. Next, the accuracy of CSM is evaluated constructing the demand spectrum using the absolute acceleration responses and pseudo acceleration responses. The results obtained using the absolute acceleration responses were found to be generally larger than those obtained using the pseudo ones. Since CSM often underestimates the response, the use of absolute acceleration response gives the response relatively closer to the exact ones. However, the difference becomes negligible as the hardening ratio and the yield strength ratio become larger.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.4
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• pp.185-191
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• 2004

A mooring system can be applied to keep the position of a floating structures. In this study, the structural analysis is carried out to analyze the dynamic characteristics of a mooring line for a floating breakwater. A three-dimensional equations of motion for a submerged chain are derived. Bending stiffness is considered for the necessary restoring force in the regions of zero tension. A fortran program is to be developed by employing finite difference method. In the algorithm, an implicit time integration and Newton-Raphson iteration are adopted. The results of simulation show good agreement in tension response pattern with the experimental results of a reference. The results of this study can contribute for the design of mooring system for a floating breakwater.

• Survey Research
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• v.11 no.2
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• pp.141-160
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• 2010

This study aims to analyze the usefulness of the survey procedures developed for telephone surveys using a random sampling method. We conducted a telephone survey of residents in a local area from October 26 to November18,2009. We applied random sampling procedures with five call-backs. Particular attention was given to the conversion of refusals. Out of 2,454 phone numbers, we succeeded in getting responses from 637 numbers. The absence of residents was the primary cause of non-response. We received responses from 45.7% of those with whom we successfully made contact. One finding of this study is that, contrary to our initial expectations, call-backs do not significantly increase the percentage of responses from young people. Also we cannot find any significant differences in responses to various questions between the responses received from the first round of calls and later responses. However, these results are not conclusive; another survey may produce different results. Therefore, further research is needed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.958-963
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• 2023

Lately, there has been increasing research on the prediction of motion performance using artificial intelligence for the safe design and operation of ships. However, compared to conventional ships, research on small fishing boats is insufficient. In this paper, we propose a model that estimates the motion response essential for calculating the motion performance of small fishing boats using a deep neural network. Hydrodynamic analysis was conducted on 15 small fishing boats, and a database was established. Environmental conditions and main particulars were applied as input data, and the response amplitude operators were utilized as the output data. The motion response predicted by the trained deep neural network model showed similar trends to the hydrodynamic analysis results. The results showed that the high-frequency motion responses were predicted well with a low error. Based on this study, we plan to extend existing research by incorporating the hull shape characteristics of fishing boats into a deep neural network model.

• Journal of The Korean Association For Science Education
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• v.32 no.1
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• pp.160-181
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• 2012

The purpose of this study is to understand raters' errors in rating performance assessments of science inquiry. For this, 60 middle school students performed scientific inquiry about sound propagation and 4 trained raters rated their activity sheets. Variance components estimation for the result of the generalizability analysis for the person, task, rater design, the variance components for rater, rater by person and rater by task are about 25%. Among 4 raters, 2 raters' severity is higher than the other two raters and their severities were stabilized. Four raters' rating agreed with each other in 51 cases among the 240 cases. Through the raters' conferences, the rater error types for 189 disagreed cases were identified as one of three types; different salience, severity, and overlooking. The error type 1, different salience, showed 38% of the disagreed cases. Salient task and salient assessment components are different among the raters. The error type 2, severity, showed 25% and the error type 3, overlooking showed 31%. The error type 2 seemed to have happened when the students responses were on the borders of two levels. Error type 3 seemed to have happened when raters overlooked some important part of students' responses because she or he immersed her or himself in one's own salience. To reduce the above rater errors, raters' conference in salience of task and assesment components are needed before performing the holistic scoring of complex tasks. Also raters need to recognize her/his severity and efforts to keep one's own severity. Multiple raters are needed to prevent the errors from being overlooked. The further studies in raters' tendencies and sources of different interpretations on the rubric are suggested.