• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.934-937
• /
• 1992

The partial discharge signal can be used as the detection signal of the deterioration of the power transformer insulation. Detecting this signal, the insulation failure and the point, in which the partial discharge is generated, could be predicted. In this paper, we study to predict the point, and find that the cross correlation method could predict the point accurately. Also, experimental system and the results are presented here.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1151-1154
• /
• 2008

The water level data sets among hydrologic observation data are correspond to the hydraulic head for each observation point and determine flow direction. The level difference among reservoir, river, and groundwater determines groundwater flow direction, just like water flows in the downstream direction because the water level of upstream point is higher than that of downstream point. We can analyze the relationship among the components in hydrologic cycle by comparing the water level differences. This research dealt with the data from Nakdong river watershed in Gyungsangnam-Do. Three data group are used for the analysis and onr group is composed of reservoir, river, and groundwater data sets. The data sets are closely(within 10 km) located in the interested area.

• Journal of Environmental Health Sciences
• /
• v.31 no.1
• /
• pp.1-6
• /
• 2005

This study was conducted to identify the runoff characteristics of non-point source according to rainfall in Nam watershed. Land-uses of the Nam watershed were surveyed paddy field 4.5%, crop field 6.8%, mountainous 78.7%, urban 2.4%, and etc. 7.7%. Mean runoff coefficients in each area were observed Ⅰ area 0.08, Ⅱ area 0.08, and Ⅲ area 0.05. In the relationship between the rainfall and peak-flow, correlation coefficients(r) were investigated Ⅰ area -0.8609, Ⅱ area 0.6035, and Ⅲ area -0.4913. In the relationship between the antecedent dry period and first flow runoff, correlation coefficients(r) were investigated Ⅰ area -0.9093, Ⅱ area -0.1039, and Ⅲ area -0.7317. The discharge of pollutant concentrations relates to the flow rate of storm-water. In the relationship between the rainfall and watershed loading, exponent values of BOD, COD, SS, and T-N were estimated to 1.2751, 1.2003, 1.3744, and 1.1262, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.253-259
• /
• 2002

The rigid body characteristics (value of mass, Position of center of mass, moments and products of inertia) of mechanical systems can be identified from FRF data or vibration spectra of rigid body motion. Therefore the accuracy of rigid body characteristics is connected directly with the accuracy of measured data for rigid body motions. In this paper, a method of improving accuracy of measurement of rigid body motion is presented. Applying rigid body theory, ail translational and rotational displacements at a tentative point on the rigid body are calculated using the measured translational displacements for several points and transfer matrix. Then the estimated displacements for the identical points are calculated using the 6 displacements of the tentative Point and transfer matrix. By using correlation coefficient between measured and estimated displacements, we can detect the existence of errors that are contained in a certain measured displacement. Consequently, the improved rigid body motion with respect to a tentative point can be obtained by eliminating the contaminated data.

• The Korean Journal of Emergency Medical Services
• /
• v.12 no.3
• /
• pp.17-26
• /
• 2008

Purpose : This study aimed to make comparison before and after CPR training for health college students (departments of visual optics, occupational therapy, and health welfare administration). The questionnaire consisted of self-efficacy, knowledge, and attitudes toward CPR affect performance ability. Through this study, the researchers tried to provide basic data in developing of cardiopulmonary resuscitation training programs and training methods for health college students. Methods : This study was applied to 83 health college students (departments of visual optics, occupational therapy, and health welfare administration) in G Province. Data were collected from September 22 to October 9, 2008. Analysis was performed by using SPSS WIN 12.0 Version program. Frequency analysis, t-test, ANOVA, and Pearson's correlation coefficients were used. Statistical significance was based on p < .05. Results : 1. There was an increase with(${\rightarrow}$ in) 1.69 point before education and 3.01 after education of artificial ventilation(p < .001). There was an increase in 1.46 point before education and 3.24 after education of airway(p < .001). There was an increase in 1.54 point before education and 2.84 after education of chest compression location(p < .001). There was an increase in 1.97 point before education and 3.13 after education of chest compression(p < .001). 2. The difference between self-efficacy, knowledge, and attitude before and after CPR education, the self-efficacy increased from 2.08 point before education(p < .001 to 3.18 point after education. Knowledge increased from 2.09 point before education(p < .001) to 3.28 point after education. Attitude increased from 1.75 point before education(p < .001 to 3.05 point after education. 3. The correlation between self-efficacy, knowledge, and attitude toward CPR), was not changed before education. After education, knowledge showed quantitative correlation(r = .219, p < .05) with attitude. 4. In regression analysis with the aim of examining influence of self-efficacy, knowledge, and attitude upon performance ability, the effect wasn't given to performance ability before education. After education, the self-efficacy was indicated to have significant effect on performance ability(p < .05).

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.13 no.4
• /
• pp.231-245
• /
• 2017

The purpose of this study is to analyze the trend line through scatter diagram analysis on correlation between SNS addiction tendencies and learning attitudes, figure out the knee point influencing learning attitudes negatively in detail, and examine influence among subareas. To address the goal, study questions are formulated as follows. First, this author did screening on the data of variables measured and analyzed descriptive statistics. Second, this researcher produced the trend line by drawing a scatter diagram in order to analyze correlation between SNS addiction tendencies, withdrawal symptoms, excessive communication, and excessive time wasting, and learning attitudes exploratorily. Third, to explore correlation between self-evaluation, learning participation, and developmental attitudes, the subfactors of learning attitudes related to SNS addiction tendencies, this author drew a scatter diagram and analyzed the threshold of positive and negative correlation. To verify the study questions, the SNS addiction tendency scale and learning attitude scale were applied to 301 university students in Chungcheong area. According to the study results, first, their learning attitudes are influenced by SNS addiction tendencies, excessive communication and excessive time wasting, and they are not influenced by withdrawal symptoms that much. Second, excessive communication, a factor of SNS addiction tendencies, and self-evaluation and developmental attitudes, factors of learning attitudes, show positive correlation to some extent and indicate negative correlation after the threshold. However, excessive communication and learning participation are found to show no correlation. Third, according to the results of examining correlation with learning attitudes by dividing them into excessive communication and excessive time wasting groups with the knee point of 1.40, as the symptom of excessive communication is found more, it influences self-evaluation, learning participation, developmental attitudes, and learning attitudes more negatively in general. The result of this study is expected to provide foundational material necessary to develop educational programs to prevent undergraduates' excessive SNS use and SNS addiction which can be used in the scenes of counseling or education.

• Research in Community and Public Health Nursing
• /
• v.10 no.1
• /
• pp.53-69
• /
• 1999

A descriptive correlation study was done to provide a basic data for comprehensive nursing care by analyzing the relationship between spiritual wellbeing, hope and perceived health status of the elderly. 195 respondents who lived at their homes and 148 respondents who lived at the facilities for elders such as nursing homes and elder's rehabilitation centers were selected and their age was over 60 years old. Paloutzian and Ellison(1982)'s spiritual wellbeing scale, Nowotny(1989)'s hope scale and Northern Illinois University's health self rating scale was used. From August 10th to August 25th, 1998, ready made questionnaires were handed out by researcher to those who can fill it out and for those who cannot fill out the questionnaires alone, the researcher read it and finished by interview. This study used Pearson's correlation coefficient for the hypothetic test and the average point and standard deviation of spiritual wellbeing, hope, and perceived health status were checked. To find out the difference between spiritual wellbeing, hope, and perceived health status by general characteristics ANOVA and Tukey test were used. The results are as follows : 1. The mean score for spiritual wellbeing of the elders was 42.27($SD{\pm}9.67$) in a possible range of 20-80. The average point of spiritual wellbeing was 2.11($SD{\pm}0.97$) point to 4 point full marks. The mean score of religious wellbeing was 21.37($SD{\pm}7.02$) and that of existential wellbeing was 20.90($SD{\pm}4.63$) in a possible range of 10 - 40. The average point of religious wellbeing was 2.14($SD{\pm}0.70$)points and existential wellbeing was 2.09($SD{\pm}0.46$) points to 4 point full marks. 2. The mean score for hope was 67.16($SD{\pm}12.28$) in a possible range of 29-116. The average point of hope was 2.31($SD{\pm}0.42$) points to 4 point full marks. 3. The mean score for perceived health status was 8.72($SD{\pm}2.49$) in a possible range of 4-14. 4. In testing the hypothesis concerning the relationship between spiritual wellbeing and hope, there was a statistically positive correlation(r=0.5209, p=0.0001). 5. In testing the hypothesis concerning the relationship between spiritual wellbeing and perceived health status, there was a statistically positive correlation(r=0.1427, p=0.0081). 6. In testing the hypothesis concerning the relationship between hope and perceived health status, there was a statistically positive correlation(r=0.2797, p=0.0001). 7. There were significant differences in spiritual wellbeing according to sex, religion, and present occupation. 8. There were significant differences in hope according to residential places, age, religion, educational level, family status, average monthly pocket money. 9. There were significant differences in perceived health status according to residential places, sex, age, educational level, present occupation and family status. From the above results it can be concluded that: There was a positive correlation between spiritual wellbeing and hope, spiritual wellbeing and perceived health status, hope and perceived health status. When the nurse implicate the nursing intervention which can be promote the spiritual wellbeing and hope, elder's perceived health status also can be improved.

• Journal of Korean Public Health Nursing
• /
• v.18 no.2
• /
• pp.342-357
• /
• 2004

A descriptive correlation study was done to provide a basic data for comprehensive nursing care by analyzing the relationship between spiritual wellbeing, hope and perceived health status of the rural elderly. 130 respondents who lived at their homes and nursing homes for elders in D county. Kyungbuk province were selected and their age was over 60 years old. Paloutzian and Ellison(1982)'s spiritual wellbeing scale. Nowotny(l989)'s hope scale and Northern Illinois University's health self rating scale was used. From September 2nd to September 30th, 2002, ready made questionnaires were handed out by researcher and two well trained nurse research assistants. to those who can fill it out and for those who cannot fill out the questionnaires alone, the researcher and assistants read it and finished by interview. This study used Pearson's correlation coefficient for the hypothetic test and the average point and standard deviation of spiritual wellbeing, hope, and perceived health status were checked. To find out the difference between spiritual wellbeing, hope, and perceived health status by general characteristics ANOVA and Tukey test were used. The results are as follows : 1. The mean score for spiritual wellbeing of the rural elders was $49.94(\pm5.62)$ in a possible range of 20-80. The mean score of religious wellbeing was $25.20(\pm3.91)$ and that of existential wellbeing was $24.74(\pm2.83)$ in a possible range of 10-40. The average point of religious wellbeing was $2.52(\pm0.39)$ points and existential wellbeing was $2.47(\pm0.28)$ points to 4 point full marks. 2. The mean score for hope was $67.68(\pm10.92)$ in a possible range of 29-116. The average point of hope was $2.33(\pm0.38)$ points to 4 point full marks. 3. The mean score for perceived health status was $9.95(\pm2.66)$ in a possible range of 4-14. The average point of perceived health status was $2.15(\pm0.72)$ point to 4 point full marks. 4. In testing the hypothesis concerning the relationship between spiritual wellbeing and hope, there was a statistically positive correlation(r=0.621. p=0.000). 5. In testing the hypothesis concerning the relationship between hope and perceived health status, there was a statistically positive correlation(r=0.305, p=0.000). 6. There were significant differences in spiritual wellbeing according to age(F=5.60, p=0.000), religion(F=11.61. p=0.000), family status(F=2.86, p=0.040) and average monthly pocket money(F=4.32, p=0.015). 7. There were significant differences in hope according to age(F=16.49, p=0.000), religion (F=3.56, p=0.009), educational level(F=8.94, p=0.000), present occupation(t=-3.13, p=0.002), family status(F=5.90, p=0.001) and average monthly pocket money(F=3.41. p=0.036). 8. There were significant differences in perceived health status according to present occupation(t=-2.16, p=0.033) average monthly pocket money(F=4.11, p=0.019). From the above results it can be concluded that: There was a positive correlation between spiritual wellbeing and hope, hope and perceived health status. There was no positive correlation between spiritual wellbeing and perceived health status. For futher study, adequate spiritual wellbeing scale and hope scale for rural elders should be developed and, age and religion factors has to be reconsidered. When the nurse implicate the nursing intervention which can be promote the spiritual wellbeing and hope, rural elder's spiritual wellbeing and hope can be improved and at the same time, their perceived health status also can be improved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.9
• /
• pp.995-1004
• /
• 2010

In the channel-varying environment, it is very important to estimate the signal to noise ratio(SNR) of received signal and to transmit the signal effectively for the modern communication system. The performance of existing non-data-aided (NDA) SNR estimation methods are substantially degraded for high level modulation scheme such as M-ary APSK or QAM. In this paper, we propose a SNR estimation method which uses zero point auto-correlation of received signal per block and auto-/cross- correlation of decision feedback signal in OFDM system. Proposed method can be studied into two Types; Type 1 can estimate SNR by zero point auto-correlation of decision feedback signal based on the second moment property. Type 2 uses both zero point auto-correlation and cross-correlation based on the fourth moment property. In block-by-block reception of OFDM system, these two SNR estimation methods can be possible for the practical implementation due to correlation based the estimation method and they show more stable estimation performance than the previous SNR estimation methods. Also, we mathematically derive the SNR estimation expression according to computational difference of auto-/cross-correlation. Finally, Monte Carlo simulations are used to verify the proposed method.

• Transactions on Electrical and Electronic Materials
• /
• v.2 no.3
• /
• pp.24-27
• /
• 2001

The end point of oxide chemical mechanical polishing (CMP) have determined by polishing time calculated from removal rate and target thickness of oxide. This study is about control of oxide removal amounts on the shallow trench isolation (STI) patterned wafers using removal rate and thickness of blanket (non-patterned) wafers. At first, it was investigated the removal properties of PETEOS blanket wafers, and then it was compared with the removal properties and the planarization (step height) as a function of polishing time of the specific STI patterned wafers. We found that there is a relationship between the oxide removal amounts of blanket and patterned wafers. We analyzed this relationship, and the post CMP thickness of patterned wafers could be controlled by removal rate and removal target thickness of blanket wafers. As the result of correlation analysis, we confirmed that there was the strong correlation between patterned and blanket wafer (correlation factor: 0.7109). So, we could confirm the repeatability as applying for STI CMP process from the obtained linear formula. As the result of repeatability test, the differences of calculated polishing time and actual polishing time was about 3.48 seconds. If this time is converted into the thickness, then it is from 104 $\AA$ to 167 $\AA$. It is possible to be ignored because process margin is about 1800 $\AA$.