• Earthquakes and Structures
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• v.11 no.6
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• pp.1143-1164
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• 2016

Time Delay of Arrival (TDOA) estimation methods based on correlation function analysis play an important role in the micro-seismic event monitoring. It makes full use of the similarity in the recorded signals that are from the same source. However, those methods are subjected to the noise effect, particularly when the global similarity of the signals is low. This paper proposes a new approach for micro-seismic monitoring based on cross wavelet transform. The cross wavelet transform is utilized to analyse the measured signals under micro-seismic events, and the cross wavelet power spectrum is used to measure the similarity of two signals in a multi-scale dimension and subsequently identify TDOA. The offset time instant associated with the maximum cross wavelet transform spectrum power is identified as TDOA, and then the location of micro-seismic event can be identified. Individual and statistical identification tests are performed with measurement data from an in-field mine. Experimental studies demonstrate that the proposed approach significantly improves the robustness and accuracy of micro-seismic source locating in mines compared to several existing methods, such as the cross-correlation, multi-correlation, STA/LTA and Kurtosis methods.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.1-12
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• 1988

This study was carried out to measure the contents of soluble sulfur and heavy metals in the leaves of roadside tree at 34 sampling sites of Seoul area from the Sep. 1 to Sep. 30 during 1985 and 1986. The results were as follows; 1. Average contents of soluble sulfur at all sampling sites were; Plantanus orientalis 0.474%, Ginkgobioloba 0.562%, and Salix pseudolasiogyne 0.566%. 2. Correlation between sulfur dioxide concentration in the air and soluble sulfur in the leaves by area were; Green belt area R = 0.985, Residential area R = 0.856, Commercial area R = 0.668, Industrial area R = 0.886. Correlation by species were ; Platanus orientalis R = 0.817, Ginkgobiloba R = 0.771, Salix pseudo-lasiogyne R = 0.824. 3. Correlation between $SO_X$ concentration in the air and sulfur contents in the leaves showed positive significance. 4. Contents of soluble sulfur in the heavy traffic area were higher than that of light traffic area. 5. Heavy metal contents of 1986 were higher than that of 1985; Fe> Mn > Zn > Pb > Cu > Cd > Cr. 6. Lead contents in the leaves of 1986 were; Platanus orientalis 16, 701 ppm, Gingobiloba 21,729ppm, Salix Pseudo-lasiogyne 12.418 ppm.

• Journal of Korean society of Dental Hygiene
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• v.17 no.4
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• pp.647-656
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• 2017

Objectives: The purpose of the study was to examine the correlation between leisure activity recognition and campus life satisfaction of dental hygiene students in the Chungnam area. Methods: A self-reported questionnaire was completed by 494 dental hygiene students at eight universities from January 11 to January 29, 2016. The questionnaire used a five point Likert scale to measure campus life satisfaction and perception towards leisure activities. Data were analyzed with descriptive statistics of variables, independent t-test, one way ANOVA, and Pearson's correlation coefficient analysis. Results: The mean for satisfaction with campus life and perception towards leisure activities were 3.15 and 3.73, respectively, wich were both higher than the average. The campus life satisfaction of facilities, study, life showed positive correlations with leisure activity recognition. Conclusions: Perception towards leisure activities was associated with satisfaction with campus life. These results suggest that university authorities should encourage students to use active leisure time such as by establishing leisure programs and club activities in order to improve students' awareness of leisure activities and encourage them to make the most of university life.

• Communications for Statistical Applications and Methods
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• v.16 no.1
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• pp.169-183
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• 2009

The simplicity and wide application of Greenberg et al. (1971) prompts to propose a set of alternative estimators of population total for multi-character surveys that elicit simultaneous information on many. sensitive study variables. The proposed estimators take into account the already known rough value of the correlation coefficient between Y(the characteristic under study) and p(the measure of size). These estimators are biased, but it is expected that the extent of bias will be smaller, since the proposed estimators are suitable for situations in between those optimum for the usual estimators and the estimators based on multi-characters for no correlation. The relative efficiency of the proposed estimators has been studied under a super population model through empirical study. It has been found through simulation study that a choice of an unrelated variable in the Greenberg et al. (1971) model could be made based on its correlation with the auxiliary variable used at estimation stage in multi-character surveys.

• Journal of Fashion Business
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• v.15 no.5
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• pp.103-114
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• 2011

During a wearer's movement, the apparel fabric layers collide each other in a highly complicated manner. The collision involves cloth-cloth, and cloth-body collision. The diversity of the textile fabrics, including silk, wool, cotton, and other synthetic fibers, together with the complex details of the apparel construction, makes the collision and other calculation procedure involved in the 3-dimensional clothing software system much more complicated. Therefore, there is a need to measure the behavior of the fabrics during the fabric collision cycles. In this study, as a first step, static measurements pertinent to the factors governing the appearance of the apparel fabrics were implemented. The drape profile, stiffness(Sd and Sf), tensile properties, thickness, and the air permeability were measured. The correlation between the parameters were calculated and reviewed. It is found that there is a high correlation of 0.97 between the actual fabric drape parameters and the 3D virtual fabric drape parameters. The measured drape coefficients of the fabrics show relatively good correlation with the measured fabric stiffness.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.53.1-53.1
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• 2011

We analyze the halo and galaxy catalogs from the Millennium simulations at redshifts z=0, 0.5, 1 to determine the alignment profiles of cluster galaxies in terms of the matter density correlation coefficient and discuss a cosmological implication our result has for breaking parameter degeneracies. For each selected cluster, we measure the alignment between the major axes of the pseudo inertia tensors from all satellites within cluster's virial radius and from only those satellites within some smaller radius. Then we average the measured values over the similar-mass sample to determine the cluster galaxy alignment profile as a function of top-hat scale difference at each redshift. It is shown that the alignment profile of cluster galaxies is well approximated by a power-law of the nonlinear density correlation coefficient that is independent of the power spectrum normalization and bias factor. The alignment profile of cluster galaxies is found to have higher amplitude and lower power-law index when averaged over the larger-mass sample and to have rather weak redshift-dependence. This result is consistent with the picture that the satellite galaxies retain the memory of the external tidal fields right after merging and infalling into the clusters but they gradually lose the initial alignment tendency as the cluster's relaxation proceeds. Demonstrating that the nonlinear density correlation coefficient varies sensitively with the density parameter and neutrino mass fraction, we discuss a potential power of the cluster galaxy alignment profile as an independent probe of cosmology.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.172-179
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• 2004

Average Bi-directional flow tube was suggested to measure single and two phase flow rate. Its working principle is similar with Pilot tube, however, it makes it possible to eliminate the cooling system which is normally needed to prevent from flashing in the pressure impulse line of Pilot tube when it is used in the depressurization condition. The suggested instrumentation was tested in the air-water vertical test section which has 80mm inner diameter and 10m length. The flow tube was installed at 120 of L/D from inlet of test section. From the test, single air and water flow rate was measured successfully. For the emasurement of two phase flow rate, Chexal drift-flux correlation was used. In the test a new correlation of momentum exchange factor was suggested. The test result shows that the suggested instrumentation using the measured void fraction and Chexal drift-flux correlation can predict the mass flow rates within $10\%$ error of measured data.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.117-126
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• 2020

This paper is aimed to explore the co-movement capital market in Southeast Asia and analysis the correlation of conventional and Islamic Index in the regional and global equity. This research become necessary to represent the risk on the capital market and measure market performance, as investor considers the volatility before investing. The time series daily data use from April 2012 to April 2020 both conventional and Islamic stock index in Malaysia and Indonesia. This paper examines the dynamics of conditional volatilities and correlations between those markets by using Multivariate Generalized Autoregressive Conditional Heteroscedasticity (MGARCH). Our result shows that conventional or composite index in Malaysia less volatile than Islamic, but on the other hand, both drive correlation movement. The other output captures that Islamic Index in Indonesian capital market more gradual volatilities than the Composite Index that tends to be low in risk so that investors intend to keep the shares. Generally, the result shows a correlation in each country for conventional and the Islamic index. However, Internationally Indonesia and Malaysia composite and Islamic is low correlated. Regionally Indonesia's indices movement looks to be more correlated and it's similar to Malaysian Capital Market counterparts. In the global market distress condition, the diversification portfolio between Indonesia and Malaysia does not give many benefits.

• The Korean Journal of Rehabilitation Nursing
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• v.8 no.2
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• pp.149-156
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• 2005

Purpose: The purpose of this study was to analyze functional independence and need for home nursing care in stroke patients. Method: This was a descriptive study. The subjects comprised 117 stroke patients who were supposed to discharge in less than a week. The instruments used for this study were the functional independence measure(FIM) and the need assessment for home nursing care of stroke patients. The data were analyzed using frequency, mean, t-test, ANOVA, and Pearson correlation coefficient. Results: Pearson correlation analysis revealed that there were negative correlations between subcategories of the FIM and the need for home nursing care in stroke patients. Especially, in case of the subjects who recorded lower scores at self-care they showed higher needs for home nursing care in the domain of physical problem and rehabilitation. Conclusion: For the operation of the home nursing care, the protocol for home nursing care is needed to the stroke patients living at home. The FIM instrument is recommended as a useful scale in order to assess the disability for the stroke patients and the need for home nursing care because this one has correlation with the scale of need for home nursing care.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1216-1221
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• 2011

We propose a multiplexed fiber Bragg grating (FBG) sensor network for vessel monitoring to measure the variation of strain and temperature by environmental perturbation based on code division multiple access (CDMA). The center wavelength of FBG was linearly changed by environmental perturbation such as strain and temperature variation so that we could be monitoring the state of sensors. A RSOA was used as optical broadband source and which was modulated by using pseudo random binary sequence (PRBS) signal. The correlation peak of reflected signal from sensor networks was measured. In this paper, we used the sliding correlation techniques for high speed response and dynamic rage of sensors.