• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.354-362
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• 2003

The aim of the present study was to establish validity for Dental Anxiety Scale in children by their drawings. Dental treatment was provied for 35 children in the ages of 4 to 8, using the quadrant approach. The children's anxiety arising during dental treatment was measured by Modified Sheskin's Criteria(Dental Anxiety Scale, DAS). After reliability analysis of Dental Anxiety Score, it was compared with Faces Pain Scale and was tested for their correlation. Thereafter the several factors having an effect on Dental Anxiety Scale were examined. A significant correlation(r=0.2610) was found between the two scales and Dental Anxiety Scale was high significantly in 4-6 score of Faces Pain Scale. The findings suggested that the Dental Anxiety Scale is a valid means of assessing child dental anxiety status in a clinical context and the Dental Anxiety Scale can be affected by 'Age', 'Gender' and 'Reaction in the past'.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.547-553
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• 2020

As aging infrastructures increase along with time, the efficient maintenance becomes more significant and accurate responses from the sensors are pre-requisite. Among various responses, strain is commonly used to detect damage such as crack and fatigue. Optical fiber sensor is one of the promising sensing techniques to measure strains with high-durability, immunity for electrical noise, long transmission distance. Fiber Bragg Grating (FBG) is a point sensor to measure the strain based on reflected signals from the grating, while Brillouin Optic Correlation Domain Analysis (BOCDA) is a distributed sensor to measure the strain along with the optical fiber based on scattering signals. Although the FBG provides the signal with high accuracy and reproducibility, the number of sensing points is limited. On the other hand, the BOCDA can measure a quasi-continuous strain along with the optical fiber. However, the measured signals from BOCDA have low accuracy and reproducibility. This paper proposed a multi-fidelity data-fusion method based on Gaussian Process Regression to improve the fidelity of the strain distribution by fusing the advantages of both systems. The proposed method was evaluated by laboratory test. The result shows that the proposed method is promising to improve the fidelity of the strain.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.2
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• pp.204-212
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• 2001

In this study, an FRF-based structural damage identification method (SDIM) is proposed for plate structures. The present SDIM is derived from the partial differential equation of motion of the damaged plate, in with damages we characterized by using a damage distribution function. The appealing features of the present SDIM include the followings. First, the modal data of the damaged structure are not required. Secondly, a sufficient number of information can be generated from the measured FRFs by simply varying excitation frequencies and response measurement points. The feasibility of the present SDIM is verified through some numerically simulated damage identification tests.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.501-504
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• 2002

본 논문에서는 최근 건축공간에 있어서 음환경에 대한 관심이 놓아지면서 학교 건축물에 있어서 강의실내의 음환경을 측정하고, 학교건축물에 대한 음환경 기준을 확립하는 데에 기초자료와 필요한 제안을 하는 것이 목적이다. 현재 음환경 기준은 단순히 소음fp밸이나 잔향 시간과 같은 단순한 물리특성만을 기준으로 하고 있다. 여기서는 강의실 내의 잔향시간, D, STI 등외 물리지표와 설문조사 등 주관적 평가를 통해 새로운 음환경 기준을 제시하려고 한다. 여기서 사용되는 물리지표로는 TSP(Time-Streched-Pulse)신호를 사용하여 잔향시간과 D(Deutlichkeit), STI(Speech Transmission index)를 산출하였다. 강의실의 화자의 위치에서 1.5m 높이에 스피커를 놓고 청취자의 위치인 여섯 점에서 무지향성 마이크로폰을 1.2m 높이에 놓고 마이크로폰으로 들어온 임펄스 응답을 측정하고, 강의실 내의 잔향시간과 D, STI를 산출하였다. 다음에 설문조사를 실시하여, 앞에서 측정한 물리지표와 설문조사를 통해 얻은 주관적 평가와의 상관관계를 파악하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.74-82
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• 2024

In this study, feature point detection and displacement measurement performance depending on feature extraction algorithms were compared and analyzed according to environmental changes and target types in the feature point-based displacement measurement algorithm. A three-story frame structure was designed for performance evaluation, and the displacement response of the structure was digitized into FHD (1920×1080) resolution. For performance analysis, the initial measurement distance was set to 10m, and increased up to 40m with an increment of 10m. During the experiments, illuminance was fixed to 450lux or 120lux. The artificial and natural targets mounted on the structure were set as regions of interest and used for feature point detection. Various feature detection algorithms were implemented for performance comparisons. As a result of the feature point detection performance analysis, the Shi-Tomasi corner and KAZE algorithm were found that they were robust to the target type, illuminance change, and increase in measurement distance. The displacement measurement accuracy using those two algorithms was also the highest. However, when using natural targets, the displacement measurement accuracy is lower than that of artificial targets. This indicated the limitation in extracting feature points as the resolution of the natural target decreased as the measurement distance increased.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.96-103
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• 2006

An MRAC-based adaptive current control scheme of an AC servo motor is presented for the performance improvement of a servo drive. Although the predictive current control is known to give ideal transient and steady-state responses, its steady-state response my be degraded under motor parameter variations. To overcome such a limitation, the disturbances caused by the parameter variations will be estimated by using an MRAC technique and compensated by a feedforward control. The proposed scheme does not require the measurement of the phase voltage unlike the conventional disturbance estimation scheme using observer. The asymptotic stability is proved. The proposed scheme is implemented using DSP TMS320C31 and the effectiveness is verified through the comparative simulations and experiments.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.12
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• pp.1308-1315
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• 2009

A full-polarimetric scatterometer(HPS: Hongik Polarimetric Scatterometer) for X-band is designed, fabricated, and verified using the theoretically well-known point-targets in this paper. The X-band full-polarimetric scatterometer consists of an OMT(Orthogonal-Mode Transducer)+horn antenna, the angle control part for the OMT+horn antenna, a transmitter/receiver with a network analyzer and a frequency-conversion circuitry, and a movable support of these parts. We use an inclinometer sensor to control the vertical and horizontal incidence angles. The full polarimetric data can be obtained because of the polarization switches and the OMT. The accuracy of the scatterometer system is verified by measuring the polarimetric RCS(Radar Cross Section) of one of the theoretically well-known point-targets, i.e., a corner reflector.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.58-66
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• 2023

In this study, cable tension was measured using the vibration method, and a vision-based system was applied as a sensor to measure the displacement response of a cable in a non-contact method. In the vision-based system, the camera is installed in a location that considers the target structure and the field of view of the camera. However, it can be difficult to recognize the control points required to measure the displacement response of a structure as the target structure and other structures such as vehicles may be included in the image at the intended installation location. In this study, a distorted image including a vehicle shows inaccurate results in image analysis due to the installation position of the vision-based system. Accordingly, the image including the vehicle was eliminated by calculating the similarity between the two images. To verify the validity of the method of estimating the cable tension of cable-stayed bridges using the proposed method, the vibration method was applied to cable-stayed bridges in service to measure the tension.

• The Journal of Korean society of community based occupational therapy
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• v.8 no.1
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• pp.1-10
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• 2018

Objective : The purpose of study is to validate the clinical utility and usability of the Korean version of the Life Space Assessment(K-LSA) which is an assessment tool of community mobility of older adults. Methods : Surveys on the clinical utility and usability of the K-LSA are carried out with a total of aoaa60 occupational and physical therapists. The surveys included the multiple choice questions on the clinical utility and open questions on the usability. Responses to multiple questions are post processed by frequency analysis and technical statistics, and responses to the open questions are categorized by common factors in each questions. Results : Average value of clinical utility ranges from 3.6 to 4.0 with positive responses of 'fair (3 point)', 'agree (4 point)' and 'strongly agree (5 point)' being 95~100%. Average value for clinical usability ranges from 3.6 to 4 with positive answers of 'fair (3 point)', 'easy (4 point)' and 'very easy (5 point)' being 88.3~100%. Additionally out of open-type questions of clinical usability, it was pointed out that the concept of 'neighborhood' for the life space level 3 and 4 is unclear. Conclusion : The current study and research outcomes showed that the K-LSA is a validated tool in Korean health care system for the clinical utility and usability in measuring community mobility, and that it is straightforward in practical use. It will help clinicians and therapists promote the social participation of older adults, and set an intervention goal for enhancing community mobility. It will further help clinicians and researchers in education and research for medical intervention and goal-setting.

• Journal of The Korean Association For Science Education
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• v.38 no.3
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• pp.355-367
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• 2018

The purposes of this study are 1) to identify systems thinking level and definition, 2) to develop a framework for the assessment of systems thinking level, and 3) to develop a rubric for scoring open-ended written responded test. In order to achieve these purposes, a total of 60 articles were analyzed by using the literature analysis framework. The systems thinking level and definition are identified through the results of systems thinking literature analysis. Based on the systems thinking level and definitions, the research derived a framework that includes the core ideas and evaluation content of each level. In addition, rubric for the scoring of open-ended response test items was revised and supplemented. It is concluded that a content validity test on the tools (systems thinking level and definition, framework for item development, rubric) has been developed in the study. The content validity was verified by 7-science education experts. According to the result of CVI, it was found to be more than .95 in all three tools. Based on the results of this study, the research will develop items that can measure students' level of systems thinking. The construct validity and criterion validity of the developed items should be verified systematically. The research could carry out a validation study for the systems thinking measurement related to the core competence emphasized in the 2015 revised curriculum.