• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.59-68
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• 2011

This study is to find out how much elementary school members have their consciousness against safety in their school. Simple questionnaire 1206 sheets have been distributed to the members and additional interview with teachers to take care of them. Statistically, frequency, and correlation analysis have been made and chi-test has also been made for data reliability. The results of these have been summarized as running on corridor with 53.4% in school safety, warming up exercise 45.2% in leisure safety, evacuation form classroom with 2.4% in fire safety, crossing around just in fromt or rear of vehicle with 61.2% in transportation safety. It is thought that safety training should be provided to more for man than for girl pupils and also, safety consciousness should be improved than all the other area.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.1
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• pp.29-39
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• 2013

The purpose of this study is to analyze middle school teachers' concern about and implementation degree of performance assessment in China. The research questions are as follows: First, what kind of concern is held by middle school teachers who implement performance assessment? Second, is there any significant difference in stages of concern the teachers on performance assessment according to their gender, education level and teaching career? Third, which level of use is shown by middle school teachers who implement performance assessment? Fourth, what is the correlation between middle school teachers' Stages of Concern and Levels of Use on performance assessment? This study was conducted based on a Concerns-Based Adoption Model (Hall, 1973; CBAM) that viewed teachers as the most primary factor of the execution of innovation, in this case, performance assessment. Performance assessment is assessment based on observation and judgement (Stiggins, 1994), and require test takers to complete a process or produce a product in a context that closely resembles real-life situations. The subjects of this study were randomly sampled from 120 middle school teachers throughout Bei-Jing, China. The questionnaires were distributed to them by mail, and they were asked to return their questionnaire by mail. The collect data were analyzed by SPSS/WIN 18.0 program in terms of frequency, correlation, or MANOVA. Frequency analysis was used to analyze concern of middle school teachers on performance assessment. To gain an frequency of the individuals in each stage, we regarded the stage in which a teacher had his/her highest score as his/her relevant stage. Correlation analysis was adopted to identify the correlation between teachers' stage of concern and level of use. To analyze the difference of the concern of China middle school teachers on performance assessment according to their individual background variables such as gender, education level, and teaching career, MANOVA was performed.

• Journal of The Korea Institute of Healthcare Architecture
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• v.28 no.4
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• pp.41-50
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• 2022

Purpose: This study aims to suggest an analysis model finding the relationship between building scale characteristics of Public-use facilities and infectious disease outbreaks around senior leisure welfare facilities and the features and their scopes where quarantine resources are to be concentrated. Methods: Reviewing previous studies found the user characteristics of senior leisure welfare facilities and scale characteristics of urban architectures. The data preprocessing was performed after collecting building data and infectious disease outbreak data in the analysis area. This study derived data for attributes of building size and frequency of infectious disease outbreaks in Public-use facilities around senior leisure welfare facilities. A computing algorithm was implemented to analyze the correlation between the building size characteristics and the infectious disease outbreak frequency as per the change of the spatial scope. Results: The results of this study are as follows: First, the suggested model was to analyze the correlation between the infection frequency and the number of senior leisure welfare facilities, the number of Public-use facilities, building area, total floor area, site area, height, building-to-land ratio, and floor area ratio varied as per the change of spatial scope. Second, correlation results varied between the infection frequency and the number of senior leisure welfare facilities, the number of Public-use facilities, building area, total floor area, site area, height, building-to-land ratio, and floor area ratio. Third, a negative correlation appeared in the analysis between the number of senior leisure welfare facilities and infection frequency. And positive correlations appeared noticeably in the study between the number of Public-use facilities, building area, total floor area, height, building-to-land ratio, and floor area ratio. Implications: This study can be used as primary data on the utilization of limited quarantine resources by analyzing the relationship between the Public-use facilities around the senior leisure welfare facilities and the spread of infectious diseases. In addition, it suggests that infectious disease prevention measures are necessary considering the spatial scope of the analysis area and the size of buildings.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.225-230
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• 2004

Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. However, the necessity of long-range detect ion of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretical analyzed and the wave velocity was confirmed with experiment The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detect ion for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested and a long-range detection has been achieved at real underground water pipelines longer than 300m.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.73-78
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• 2000

On this study, the fatigue crack propagation of super duplex stainless steel is investigated in conditions of various volume fraction of austenite phase by changing heat treatment temperature. And we analysed acoustic emission signals during the fatigue test by time-frequency analysis methods. As the temperature of heat treatment increased, volume fraction of austenite decreased and coarse grain was obtained. The specimen heat treated at $1200^{\circ}C$ had longer fatigue life and slower rate of crack growth. As a result of time-frequency analyze of acoustic emission signals during fatigue test, main frequency was $200{\sim}300kHz$ having no correlation with heat treatment and crack length, and 500kHz was obtained by dimple and separate of inclusion

• Journal of Korean Elementary Science Education
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• v.38 no.3
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• pp.331-344
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• 2019

This study aims to analyse science-gifted elementary students' perception of speech in general school class, school science class, and science-gifted class and the relationship between their voluntary speech and scientific creativity. For this, 39 fifth-graders in the Science-Gifted Education Center at Seoul Metropolitan Office of Education in Korea were asked about their frequency of voluntary speech on each class situation, the reasons for such behavior, and their general opinions about speech. Also, researchers collected the teachers' observation on students' speech in class. To get the scores for students' scientific creativity, four different subjects of tasks were presented. The students' scientific creativity scores were used for correlation analysis with their frequency of speech. The main findings from this study are as follows: First, science-gifted elementary students tended to be passive in science-gifted class compared to general school and school science class. Second, the main reason for the low frequency of students' speech in school classes is that they do not have many opportunities to make presentations. Third, a survey of students' general thoughts on speech showed that more students wanted to make a speech voluntarily in class than the opposite. Fourth, the four different scientific creativity tasks had little correlation. Fifth, the correlations between the frequency of voluntary speech and the scores of scientific creativity were mostly low, with significant results only for plant task. Sixth, the correlations between the frequency of voluntary speech and the two components that make up scientific creativity, originality and usefulness, were also mostly low, but significant results for both were found in plant task, with originality having a higher correlation than usefulness. Based on this results, this study discussed the meanings and implications of students' voluntary speech on elementary science education and creativity education.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.288-294
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• 2015

Recently, the module-integrated converter has shown an interest in the photovoltaic generation system. In this system, the high frequency transformer should be compact and efficient. The proposed method is based on the correlation characteristic between the copper and core loss to minimize the loss of transformer. By sizing an effective cross-sectional area and window area of core, the amount of loss is minimized. This paper presents the design and analysis of high frequency transformer by using the 3D finite element model coupled with DC-DC converter circuit for more accurate analysis by considering the nonlinear voltage and current waveforms in converter circuit. The current waveform in each winding is realized by using the ideal DC voltage source and switching component. And, the thermal analysis is performed to satisfy the electrical and thermal design criteria.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.191-192
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• 2019

The construction industry is in the process of changing from the existing labor-intensive production system to a construction automation system using advanced information and communication technologies. Accordingly, in order to identify key research areas and utilization technologies in the field of construction automation, this study collected the latest 17 years (2000-2016) of papers published in International Symposium on Automation and Robotics in Construction (ISARC) and conducted a correlation analysis between the construction management areas and automation technologies based on the keyword frequency. As a result, the BIM, WSN, and Augmented reality were extracted as the technology keywords with high correlation with various areas of construction management.

• Structural Engineering and Mechanics
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• v.13 no.6
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• pp.671-694
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• 2002

This paper presents theoretical investigation on the cross correlation between torsional vibration ($u_{\theta}$) and translation vibration ($u_x$) of asymmetrical structure under white noise excitation. The formula reveals that the cross correlation coefficient (${\rho}$) is a function of uncoupled frequency ratio (${\Omega}={\omega}_{\theta}/{\omega}_x$), eccentricity, and damping ratio (${\xi}$). Simulations involving acceleration records from fifteen different earthquakes show correlation coefficients results similar to the theoretical correlation coefficients. The uncoupled frequency ratio is the dominating parameter to ${\rho}$; generally, ${\rho}$ is positive for ${\omega}_{\theta}/{\omega}_x$ > 1.0, negative for ${\omega}_{\theta}/{\omega}_x$ < 1.0, and close to zero for ${\omega}_{\theta}/{\omega}_x$ = 1.0. When the eccentricity or damping ratio increases, ${\rho}$ increases moderately for small ${\Omega}$ (< 1.0) only. The relation among $u_x$, $u_{\theta}$ and corner displacement are best presented by ${\rho}$; a simple way to hand-calculate the theoretical dynamic corner displacements from $u_x$, $u_{\theta}$ and ${\rho}$ is proposed as an alternative to dynamic analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1A
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• pp.73-81
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• 2012

In this paper, we propose a high-speed synchronization method for Digital Radio Mondiale (DRM) receivers. In order to satisfy the high-speed synchronization requirement of DRM receivers, the proposed method eliminate the initial sampling frequency synchronization process in conventional synchronization methods. In the proposed method, sampling frequency tracking is performed after integer frequency synchronization and frame synchronization. Different correlation algorithms are applied to detect the first frame of the Orthogonal Frequency Division Multiplexing (OFDM) demodulation symbol with sampling frequency offset (SFO). A frame detection algorithm that is robust to SFO is selected based on the performance analysis and simulation. Simulation results show that the proposed method reduces the time spent for initial sampling frequency synchronization even if SFO is present in the DRM signal. In addition, it is verify that inter-cell differential correlation used between reference cells is roubst to the effect of initial SFO.