• Structural Engineering and Mechanics
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• v.59 no.6
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• pp.1037-1054
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• 2016

Structural parameter evaluation and external force estimation are two important parts of structural health monitoring. But the structural parameter identification with limited input information is still a challenging problem. A new simultaneous identification method in time domain is proposed in this study to identify the structural parameters and evaluate the external force. Each sampling point in the time history of external force is taken as the unknowns in force evaluation. To reduce the number of unknowns for force evaluation the time domain measurements are divided into several windows. In each time window the structural excitation is decomposed by orthogonal polynomials. The time-variant excitation can be represented approximately by the linear combination of these orthogonal bases. Structural parameters and the coefficients of decomposition are added to the state variable to be identified. The extended Kalman filter (EKF) is augmented and selected as the mathematical tool for the implementation of state variable evaluation. The proposed method is validated numerically with simulation studies of a time-invariant linear structure, a hysteretic nonlinear structure and a time-variant linear shear frame, respectively. Results from the simulation studies indicate that the proposed method is capable of identifying the dynamic load and structural parameters fairly accurately. This method could also identify the time-variant and nonlinear structural parameter even with contaminated incomplete measurement.

• Women's Health Nursing
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• v.22 no.1
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• pp.30-38
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• 2016

Purpose: This study was conducted to examine effects of a sexual function improvement program on sexual distress, sexual satisfaction and marital intimacy among breast cancer survivors. Methods: With quasi-experimental design, a total of 54 women after breast surgery were assigned into experimental group (n=28) and control group (n=26) after recruited via convenience sampling. They were endocrine surgery outpatients in university hospital at Chonnam province. Experimental group received a sexual function improvement program 5 sessions over 5 weeks. Sexual distress, sexual satisfaction, and marital intimacy were examined with self-report structured questionaries. Data were analyzed using $x^2$ test, Fisher's exact, independent t-test, and analysis of covariance with SPSS 17.0/window program. Results: Women who participated in the sexual function improvement program had lower sexual distress (F=27.29, p<.001), higher sexual satisfaction (t=3.09, p=.003) higher marital intimacy (F=17.51, p<.001) than the women who did not participate. Conclusion: Results suggest that a sexual function improvement program can be effective strategy to improve sexual distress, sexual satisfaction and marital intimacy. Therefore, this program can be regarded as useful nursing intervention program for breast cancer survivors.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.319-327
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• 2011

An iterative technique based on orthogonal filters and frequency tracking is proposed to estimate harmonic components in power systems. The technique uses frequency interpolation to estimate fundamental frequency and harmonics when the nominal frequency of the signal is a non-integer value. Due to the number of computations involved during the generation of filter coefficients, an offline computation is suggested. Beneficial features of the proposed technique include fixed sampling rate and fixed data window size. The performance of the proposed technique is examined by simulating different power system operating conditions and evaluating the data from these simulations. A technique based on Fast Fourier Transform is also used to estimate the harmonic components for all the simulated signals. These estimates are compared with those obtained from the proposed technique. Results show that the proposed technique can converge to the accurate fundamental frequency and therefore, provide accurate harmonic components even when the fundamental frequency is not equal to the nominal frequency.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1654-1668
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• 1992

The acoustic field resulted by the radiation of sound from vibrating structure is predicted based on the sound pressure measurements. The sound pressures are measured at discreate point on the measurement plane ; Hologram. Based on these discreate measurements, the sound field away from the acoustic source is constructed based on the discreate form of Kirchhoff-Helmohltz integral equations The velocities, intensities, and pressures of arbitrary plane of interest in space are predicted and visualized The effects on the sound field reconstruction ; finite aperture effect, effect of finite sampling interval in space studied in terms of wraparound error and spatial aliasing. Numerical simulations and experimental verifications are performed to see these effects. To reduce the wraparound error, zero padding technique in space is used and the usefulness of the method is demonstrated by various examples.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.44-50
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• 2002

The fast Fourier transform (FFT) is a good method to estimate spectral density, but the frequency resolution is limited to the sampling window, and thus the precise characteristics of the spectral density for short signals are not clear. To solve the limitation, a multiple band-pass filter was introduced to estimate the precise time course of the spectral density for flash visual evoked potentials (VEPs). Signals were recorded during -200 and 600 ms using balanced noncephalic electrodes, and sampled at 1 K Hz in 12 bits. With 1 Hz and 10 ms resolutions, spectral density was estimated between 10 and 100 Hz. Background powers at the alpha-and beta-bands were high over the posterior scalp, and powers around 200ms were evoked at the same bands over the same region, corresponding to P110 and N165 of VEPs. normalized's spectral density showed evoked powers around 200 ms and suppressed powers following the evoked powers over the posterior scalp. The evoked powers above the 20Hz band were not statistically significant. However, the gamma band was significantly evoked intra-individually; details in the gamma bands were varied among the subjects. Details of spectral density were complicated even for a simple task such as watching flashes; both synchronization and desynchronization occurred with different distributions and different time courses.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.257-258
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• 2006

In this paper, we address several issues in the real time implementation of MPEG-1 Layer II decoder on a fixed-point digital signal processor (DSP), especially TMS320C6416. There is a trade-off between processing speed and the size of program/data memory for the optimal implementation. In a view of the speed optimization, we first convert the floating point operations into fixed point ones with little degradation in audio quality, and then the look-up tables used for the inverse quantization of the audio codec are forced to be located into the internal memory of the DSP. And then, window functions and filter coefficients in the decoder are precalculated and stored as constant, which makes the decoder faster even larger memory size is required. It is shown from the real-time experiments that the fixed-point implementation enables us to make the decoder with a sampling rate of 48 kHz operate with 3 times faster than real-time on TMS320C6416 at a clock rate of 600 MHz.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.1
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• pp.7-14
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• 2017

Purpose: Since the large hospitals are one of the most intensive energy users among building types in Korea, it is important to investigate and apply appropriate energy conservation measures. There are many researches on energy conservation measures for HVAC system in hospitals, but only few useful guidelines for envelope design variables were existed. The building envelope is one of the important factors to building energy consumption and patients' comfort. The purpose of this study is to suggest the most influential envelope design variables for each end-use energy demand. Methods: 100 samples were generated by LHS(Latin Hypercube Sampling) method. After energy performance simulation, global sensitivity analysis was performed by the regression method. DesignBuilder, Simlab 2.2 and JEPlus were used in this process. Results: The most influencing variables are SHGC, SHGC and VT for heating, cooling, and lighting, respectively. However, the most influencing variable for total energy demand is WWR(Window to Wall Ratio). The analysis was conducted based on the coefficient of variance results. Implications: The six envelop design variables were ranked according to the end-use energy demand.

• Korean Security Journal
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• no.37
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• pp.7-28
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• 2013

Based on the status of which the research is not active and the analysis is not progressed, the purpose of this study life up pride, value and professional ethic of private security guard. Also, through this research, it offers the effect on professional ethic, organizational trust and job satisfaction. The data collection and survey are taken by the private security business members who work staff member or manager. They are surveyed with convenience sampling that among 500 data, 46 data which are thought to be answered insincerely or lack are excluded, so the total of 454 answered data are included in the final analysis. After coding and input process, the data is analyzed by factor analysis, reliability analysis, correlation analysis and multiple regression analysis using window SPSS 19.0 version. Significance level is 0.05. The conclusion that has been made based on the statistical analysis results are the followings. Professional ethic has a positive impact on organizational trust, job satisfaction. The educational training of the company is connected job satisfaction resultantly. Also the professional ethics education will improve the ability of the individual. Finally, the professional ethics raises a job satisfaction. Also, Organizational trust has a positive impact on job satisfaction. This the while to agree with a research result about the other type of business worker who is researched. In order raising the job satisfaction, the effort for raising a organizational trust is necessary.

• Korean Journal of Environment and Ecology
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• v.37 no.4
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• pp.289-301
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• 2023

Forests within watersheds are essential in maintaining ecosystems and are the central infrastructure for constructing an ecological network system. However, due to indiscriminate development projects carried out over past decades, forest fragmentation and land use changes have accelerated, and their original functions have been lost. Since a forest's structural pattern directly impacts ecological processes and functions in understanding forest ecosystems, identifying and analyzing change patterns is essential. Therefore, this study analyzed structural changes in the forest landscape according to the time-series land cover changes using the FRAGSTATS model for the dam watershed of the Geum River upstream. Land cover changes in the dam watershed of the Geum River upstream through land cover change detection showed an increase of 33.12 square kilometers (0.62%) of forests and 67.26 square kilometers (1.26%) of urbanized dry areas and a decrease of 148.25 square kilometers (2.79%) in agricultural areas from the 1980s to the 2010s. The results of no-sampling forest landscape analysis within the watershed indicated landscape percentage (PLAND), area-weighted proximity index (CONTIG_AM), average central area (CORE_MN), and adjacency index (PLADJ) increased, and the number of patches (NP), landscape shape index (LSI), and cohesion index (COHESION) decreased. Identification of structural change patterns through a moving window analysis showed the forest landscape in Sangju City, Gyeongsangbuk Province, Boeun County in Chungcheongbuk Province, and Jinan Province in Jeollabuk Province was relatively well preserved, but fragmentation was ongoing at the border between Okcheon County in Chungcheongbuk Province, Yeongdong and Geumsan Counties in Chungcheongnam Province, and the forest landscape in areas adjacent to Muju and Jangsu Counties in Jeollabuk Province. The results indicate that it is necessary to establish afforestation projects for fragmented areas when preparing a future regional forest management strategy. This study derived areas where fragmentation of forest landscapes is expected and the results may be used as basic data for assessing the health of watershed forests and establishing management plans.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.309-316
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• 2018

Purpose: This study was conducted to identify the prevalence and related factors of metabolic syndrome in Korean adolescents. Method: Based on data from the Korea National Health and Nutrition Examination Survey of 2015, 404 adolescents aged 12-18 years were enrolled. We used the adolescent Ford method as the diagnostic criteria for adolescent metabolic syndrome. The data were analyzed using descriptive statistics, t-test, $x^2$-test, and logistic regression with SPSS WINDOW 23.0 program. Results: The prevalence of metabolic syndrome in Korean adolescents was 6.5% (6.5% for boys and 6.4% for girls). Among metabolic syndrome components, the prevalence of elevated blood pressure (28.8%) was the highest, followed by elevated triglycerides (21.3%), increased waist circumference (14.1%), decreased high density lipoprotein-cholesterol (11.5%), and elevated fasting blood sugar (7.8%). The only factor associated with metabolic syndrome in both boys and girls was the Body Mass Index (BMI), and the likelihood of a metabolic syndrome increased by 1.6 to 2.3 times (Adjusted OR=1.552 to 2.313, p=0.001) as the BMI increased. Conclusion: Based on the results of this study, an intervention program should be developed and provided to maintain the BMI in the normal range for the prevention and management of metabolic syndrome in Korean adolescents.