• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.1
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• pp.1-5
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• 2010

Purpose : This research inquires into the effect of applying microcurrent (MC) according to various frequency levels on the pain and functional recovery of patients with chronic back pain. Methods : Thirty participants with chronic lower back pain disease were divided equally into three experimenta l groups. The MC frequency used in the first experimental group was 0.5Hz, the second experimental group was 50Hz, and the third experimental group was 100Hz for 20 minute sessions. A hot pack and ultrasound were applied to all groups as the general physical therapy. Measurements were taken using the visual analogue scale (VAS), the face pain rating scale (FPRS), and the Oswestry disability index (001). The analysis used the paired t-test in order to compare pretest and posttest results. A one-way ANOVA was performed to make comparisons with regards to frequency levels. Results : VAS, FPRS, and 001 showed significant pain decrease in all groups except for the 001 measurement in the 0.5 Hz group. There were no significant differences according to frequency levels. Conclusion: For chronic pain and functional recovery, a microcurrent produces an effect after treatment. However, results did not show a significant difference in change obtained from differing frequency levels.

• Journal of Auto-vehicle Safety Association
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• v.12 no.3
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• pp.27-33
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• 2020

In this paper, the process of predicting efficient durability performance for vibration durability test of automobile parts using vibration test load on automobile fuel tank is presented. First of all, the common standard load that can be applied to the initial development process of the automobile was used for the fuel tank and the vulnerability of the fuel tank to the vibration fatigue load was identified through frequency response analysis. In addition, the vulnerability of the fuel tank was re-enacted through vibration durability test results, and the scale factor was applied to the standard load. In order to predict the vibration durability performance required for detailed design, vibration fatigue analysis was performed on the developed vehicle with the frequency of vibration severity equivalent to the durability test, and the vulnerability and life span of the fuel tank were identified through the process of applying weights to these selected standard loads, thereby reducing the test time of the development vehicle.

• Journal of Korean Academy of Nursing Administration
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• v.10 no.1
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• pp.141-159
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• 2004

Purpose: The purpose of this study was to investigate the degree of information technology application, and to identify the effect of information technology application en knowledge management process in clinical nurses. Method: Participants were 629 regular clinical nurses who had worked for over 1 year in general units of 9 tertiary medical hospitals including 2 national university hospitals, 5 university hospitals, and 2 hospitals founded by business enterprises. Data were collected from March to May 2003 through questionnaires. Thee structured instruments were used to collect the data: Information Technology Application scale, Knowledge Management Process Scale(Jeong, Lee, Lee, & Kim, 2003), and one for general characteristics. The data were analyzed using reliability analysis, descriptive analysis, one-way ANOVA, $Scheff{\acute{e}$ test, correlation analysis, partial correlation analysis, and multiple regression analysis with the SPSS for Windows 10,0 program. Result: 1) The HIS application degree, IT application ability, and IT application frequency were significantly correlated with the degree of knowledge management process activation and 4 elements of knowledge management process, Knowledge Creation, Knowledge Storage, Knowledge Sharing, and Knowledge Utilization(p=.000). 2) The 3 variables, HIS application degree, IT application ability, and IT application frequency explained 47.2% of the total variance of the degree of knowledge management process activation, and 352% of me total variance of Knowledge Storage. And 2 variables, HIS application degree and IT application frequency explained 17.6% of the total variance of Knowledge Creation, 39.9% of the total variance of Knowledge sharing, and 33.8% of the total variance of Knowledge utilization(p=.000). 3) As a result of multiple regression analysis, the key determinant of the degree of knowledge management process activation for nurses was HIS application degree The HIS application degree, IT application frequency, position, IT application ability, and continuous total numbers of years working at the present hospital explained 51.1% of the total variance of the degree of knowledge management process activation(p=.000). Conclusions: These results suggest that the information technology application positively affects the nurses' knowledge management process. From the above findings, information technology application is empirically verified as a useful and effective method to activate knowledge management process, and knowledge management.

• Earthquakes and Structures
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• v.3 no.6
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• pp.839-852
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• 2012

Earthquake records are often analyzed in various earthquake engineering problems, making time-frequency analysis for such records of primary concern. The best tool for such analysis appears to be based on wavelet functions; selection of which is not an easy task and is commonly carried through trial and error process. Furthermore, often a particular wavelet is adopted for analysis of various earthquakes irrespective of record's prime characteristics, e.g. wave's magnitude. A wavelet constructed based on records' characteristics may yield a more accurate solution and more efficient solution procedure in time-frequency analysis. In this study, a low-pass reconstruction filter is obtained for each earthquake record based on multi-resolution decomposition technique; the filter is then assigned to be the normalized version of the last approximation component with respect to its magnitude. The scaling and wavelet functions are computed using two-scale relations. The calculated wavelets are highly efficient in decomposing the original records as compared to other commonly used wavelets such as Daubechies2 wavelet. The method is further advantageous since it enables one to decompose the original record in such a way that a clear time-frequency resolution is obtained.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.187-189
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• 2003

Almost all building/infrastructures made of composite materials are fabricated without proper design. Unlike airplane or automobile parts, prototype test is impossible. One cannot destroy 10 story buildings or 100-meter long bridges. People try to build 100-story buildings or several thousand meter long bridges. In order to realize "composites in construction", the following subjects must be studied in detail, for his design: Concept optimization, Simple method of analysis, Folded plate theory, Size effects in failure, and Critical frequency. Unlike the design procedure with conventional materials, his design should include material design, selection of manufacturing methods, and quality control methods, in addition to the fabrication method.on method.

• Journal of Integrative Natural Science
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• v.1 no.3
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• pp.221-229
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• 2008

본 논문에서는 기존의 개인 식별 방법의 한계를 해결하는 대안으로 떠오르고 있는 생체인식 기술 중 인식률이 뛰어나고 신뢰성 있는 홍채인식 시스템을 구현하고자 한다. 구현을 위하여 신호처리 분야에서 주로 사용되는 wavelet변환으로 계수 특징 값 추출을 하였으며, 인식률을 알아보기 위하여 신경망 기법을 이용하고자 한다. 그러나 신경망 기법에서 주로 사용되는 비선형 최적화기법인 Scale Conjugate Gradient는 최적화 문제점을 해결하기에는 수렴속도가 느리기 때문에 적합하지 않다. 따라서 본 논문에서는 기존 Scale Conjugate Gradient를 보완한 Levenberg-Marquardt Back-Propagation을 홍채인식에 적용하여 구현함으로써 인식율을 높이고자 한다. 적용한 알고리즘 구현으로 해의 수렴정도, 변수 벡터의 변화정도에 따라 크기를 적절히 변화시킴으로써 수렴속도를 개선하고, 효율성과 안정성을 동시에 얻을 수 있었다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.11
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• pp.616-621
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• 2000

This paper deals with the multiresolution analysis of wavelet transform for partial discharge(PD). Test arrangement is based on the needle-plane electrode system and applied AC high voltage. The measured PD signal was decomposed into "approximations" and "details". The approximation are the high scale, low-frequency components of the PD signal. The details are the low-scale, high frequency components. The decomposition process are iterated to 3 level, with successive approximation being decomposed in turn, so that PD signal is broken down into many lower-resolution components. Through the procedure of signal wavelet transform, signal noise extraction and signal reconstruction, the signal is analyzed to determine the magnitude of PD.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.177-181
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• 2004

In this paper, we suggest an Iris recognition system with an excellent recognition rate and confidence as an alternative biometric recognition technique that solves the limit in an existing individual discrimination. For its implementation, we extracted coefficients feature values with the wavelet transformation mainly used in the signal processing, and we used neural network to see a recognition rate. However, Scale Conjugate Gradient of nonlinear optimum method mainly used in neural network is not suitable to solve the optimum problem for its slow velocity of convergence. So we intended to enhance the recognition rate by using Levenberg-Marquardt Back-propagation which supplements existing Scale Conjugate Gradient for an implementation of the iris recognition system. We improved convergence velocity, efficiency, and stability by changing properly the size according to both convergence rate of solution and variation rate of variable vector with the implementation of an applied algorithm.

• Wind and Structures
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• v.9 no.3
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• pp.193-215
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• 2006

This paper presents an analysis of wind velocity measurements obtained from four ultrasonic anemometers arranged in a vertical formation. The anemometers were located in a rural environment with a view to providing detailed information on the flow statistics of the lower part of the atmospheric boundary layer, particularly for the extreme wind events that are important in loading calculations. The data is analysed using both conventional analysis and conditional sampling. The latter is combined with wavelet analysis in order to provide a detailed analysis of the energy/frequency relationship of the extreme events. The work presented in this paper suggests that on average the extreme events occur as a result of the superposition of two independent mechanisms - large scale events that scale on the atmospheric boundary layer thickness and small scale events a few tens of metres in size.

• Structural Engineering and Mechanics
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• v.67 no.5
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• pp.517-525
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• 2018

In this study, we investigate the vibration of single-walled carbon nanotubes embedded in a polymeric matrix using nonlocal elasticity theories with account arbitrary boundary conditions effects. A Winkler type elastic foundation is employed to model the interaction of nanobeam and the surrounding elastic medium. Influence of all parameters such as nonlocal small-scale effects, Winkler modulus parameter, vibration mode and aspect ratio of nanobeam on the vibration frequency are analyzed and discussed. The mechanical properties of carbon nanotubes and polymer matrix are treated and an analytical solution is derived using the governing equations of the nonlocal Euler-Bernoulli beam models. Solutions have been compared with those obtained in the literature and The results obtained show that the non-dimensional natural frequency is significantly affected by the small-scale coefficient, the vibrational mode number and the elastic medium.