• Smart Structures and Systems
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• 제15권1호
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• pp.81-97
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• 2015

Recently, a new output-only modal identification method based on time-frequency independent component analysis (ICA) has been developed by the authors and shown to be useful for even highly-damped structures. In many cases, it is of interest to identify the complex modes of structures with non-proportional damping. This study extends the time-frequency ICA based method to a complex ICA formulation for output-only modal identification of non-proportionally-damped structures. The connection is established between complex ICA model and the complex-valued modal expansion with sparse time-frequency representation, thereby blindly separating the measured structural responses into the complex mode matrix and complex-valued modal responses. Numerical simulation on a non-proportionally-damped system, laboratory experiment on a highly-damped three-story frame, and a real-world highly-damped base-isolated structure identification example demonstrate the capability of the time-frequency complex ICA method for identification of structures with complex modes in a straightforward and efficient manner.

• Structural Engineering and Mechanics
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• 제56권2호
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• pp.293-315
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• 2015

While most of researches on system identification of building structures are aimed at finding modal parameters first and identifying the corresponding physical parameters by using the transformation in terms of transfer functions and cross spectra, etc., direct physical parameter system identification methods have been proposed recently. Due to the problem of signal/noise (SN) ratios, the previous methods are restricted mostly to earthquake records or forced vibration data. In this paper, a theoretical investigation is performed on the influence of wind disturbances on stiffness identification of building structures using micro-tremor at limited floors. It is concluded that the influence of wind disturbances on stiffness identification of building structures using micro-tremor at limited floors is restricted in case of using time-series data for low-rise buildings and does not cause serious problems.

• Structural Engineering and Mechanics
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• 제70권2호
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• pp.209-219
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• 2019

By normalizing the internal hysteresis variable and eliminating the redundant parameter, the normalized Bouc-Wen model is considered to be an improved and more reasonable form of the Bouc-Wen model. In order to facilitate application and further research of the normalized Bouc-Wen model, some key aspects of the model need to be uncovered. In this paper, hysteresis characterization of the normalized Bouc-Wen model is first studied with respect to the model parameters, which reveals the influence of each model parameter to the shape of the hysteresis loops. The parameter identification scheme is then proposed based on an improved genetic algorithm (IGA), and verified by experimental test data. It is proved that the proposed method can be an efficacious tool for identification of the model parameters by matching the reconstructed hysteresis loops with the target hysteresis loops. Meanwhile, the IGA is shown to outperform the standard GA. Finally, a simplified identification method is proposed based on parameter sensitivity, which indicates that the efficiency of the identification process can be greatly enhanced while maintaining comparable accuracy if the low-sensitivity parameters are reasonably restricted to narrower ranges.

• 대한임베디드공학회논문지
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• 제17권1호
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• pp.67-76
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• 2022

Monostatic/Bistatic inverse synthetic aperture radar (ISAR) images are two-dimensional radar cross section (RCS) distributions of a target. When there are many targets in a single radar beam, ISAR images are generated with targets overlapped, so it is difficult to perform the targets identification using the trained database. In addition, it is inefficient to perform target identification using only single monostatic and bistatic ISAR images separately because each method has its own advantages and weaknesses. Therefore, this paper analyzes multiple targets identification performances using monostatic/bistatic ISAR images and proposes a method of identification through fusion of two ISAR images. To identify multiple targets, we use image combination technique using trained single target images. Simulation results show effectiveness of proposed method.

• 전력전자학회논문지
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• 제27권6호
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• pp.455-463
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• 2022

This study proposes a receiving pad identification coil for wireless charging of electric vehicles. The proposed coil identifies the shape of the receiving pad through magnetic coupling with the receiving pad. Therefore, the shape of the coil is designed to show the different magnetic properties of each receiving pad. The accuracy of this design is verified through finite element method simulation. Furthermore, the operation method of the secondary pad identification circuit is described, and the appropriate magnitude and length of the pulse voltage applied to this circuit for receiving pad identification are derived through simulation. The performance of the proposed identification coil set is verified by the experimental results.

• Asia Marketing Journal
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• 제9권1호
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• pp.1-22
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• 2007

조직동일시의 개념을 활용하여서 세일즈맨의 성과를 향상시키는 것이 이 논문의 주제이다. 세일즈맨의 성과가 주요 결과변수이고, 조직에의 가입기간, 조직의 지각된 인지도, 조직간의 경쟁이 주요 독립변수이다. 개념적 틀에 기초한 여섯 개의 가설들 중에서 다섯 개가 구조방정식 모형을 통하여서 지지되었다. 몇 개의 시사점들이 제시되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.339-340
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• 2010

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.52.4-52
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• 2002

$\textbullet$ Introduction $\textbullet$ Wiener system identification problem $\textbullet$ Identification method $\textbullet$ Simulation $\textbullet$ Conclusions $\textbullet$ References

• Human Ecology Research
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• 제54권1호
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• pp.97-106
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• 2016

The purposes of this study were to examine the effect of consumers brand identification of a luxury fashion brand on brand attachment and to determine the moderating influences of self-monitoring and social self-esteem on this effect. For this study, a questionnaire was developed through a literature search. The developed survey was then conducted by means of on-line and off-line questionnaires. Data from 228 women with experience in buying luxury fashion brands was analyzed with descriptive statistics, Cronbach a, factor analysis, regression, two-way one-way analysis of variance (ANOVA) and t -test using SPSS for Windows 21.0. First, the brand identification of consumer was composed three factors; actual, ideal, social identification. The brand attachment was composed five factors; emotional, dependency, attraction, intellectual curiosity, and general interest. Second, it was shown that brand identification has a positive influence on brand attachment. Third, it was also shown that there is a moderating influence from self-monitoring on the effect of consumer's brand-identification of a luxury fashion brand on brand attachment. Interaction effect between consumer's brand-identification and self-monitoring was found out to be meaningful at brand affect. Fourth, there was an additional moderating effect from social self-esteem on this effect. Interaction effect between consumer's brand-identification and social self-esteem was found out to be meaningful at brand affect.

• 대한한의진단학회지
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• 제17권1호
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• pp.29-44
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• 2013

Objectives This study is aimed at assessing the reliability of the Pattern identification questionnaire (PIQ) developed by Korea Institute of Oriental Medicine and examining the validity of the PIQ by comparing the pattern identification scores of different groups. Methods We conducted a survey of 258 participants (79 teachers and 179 graduate students at one School of Korean Medicine) using self-reported questionnaire and all the samples were retested. The test-retest reliability was assessed by Kappa coefficient(${\kappa}$) and Pearson correlation coefficient. Also we compared the differences in pattern identification scores according to sex, age and occupation. Results 1. One of 116 questions are impossible to calculate; 22 of them (18.97%) scored under 0.4 in ${\kappa}$; 90(77.59%) ranged from 0.4 to 0.8 in ${\kappa}$; and three questions (3.58%) scored 0.8 or over in ${\kappa}$. 2. Pearson correlation coefficients between test score and retest score of all pattern identification items are 0.4 or over. 3. The mean score for pattern identification in women was generally higher than that in men, particularly in patterns of blood-deficiency, blood-stasis, yang-deficiency and kidney disease. 4. The mean score for pattern identification in the graduate student group was generally higher than that in the teacher group. Conclusion In test-retest reliability, the PIQ showed relatively high reliability. The mean pattern identification score showed differences in regards to retaining knowledge about Korean medicine. Therefore, future research involving modification of questionnaire items and confirming the validity of this questionnaire is required.