• Journal of the Korean Society for Nondestructive Testing
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• v.11 no.2
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• pp.22-31
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• 1991

Various types of ultrasonic techniques have been used for the estimation of compressive strength of concrete structures. However, conventional ultrasonic velocity method using only longitudial wave cannot be determined the compressive strength of concrete structures with accuracy. In this paper, by using the introduction of multiple parameter, e. g. velocity of shear wave, velocity of longitudinal wave, attenuation coefficient of shear wave, attenuation coefficient of longitudinal wave, combination condition, age and preservation method, multiple regression analysis method was applied to the determination of compressive strength of concrete structures. The experimental results show that velocity of shear wave can be estimated compressive strength of concrete with more accuracy compared with the velocity of longitudinal wave, accuracy of estimated error range of compressive strength of concrete structures can be enhanced within the range of ${\pm}$10% approximately.

• Korean Journal of Psychosomatic Medicine
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• v.3 no.1
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• pp.49-57
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• 1995

To evaluate body image disturbance in Korea, the Body Image Scale(BIS) was developed and it's reliability and validity was tested. The BIS was administered to 33 subjects of normal controls and 64 patients consisting of mainly neurotic patients. The correlation coefficient, of test-retest reliability with an interval of 2 weeks was 0.88 and internal consistency coefficient Cronbach's alpha, was 0.80. Discriminant validity test indicated that there were significant differences in total BIS score between normal control group and psychiatric patients group after controlling the effects of age, sex, and educational level. Factor analysis showed two distinct dimensions, namely 'physical appearance' and 'physical health and strength'. The BIS appears to be a reliable, internally consistent and valid scale which can be used for assessing body image in Korea pupulations.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.11
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• pp.1307-1317
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• 2003

The level of consumer knowledge has been gradually increased with the growth of living standard of consumer and the development of communication technology. The purpose of this study was to investigate the structure and measure of consumer knowledge and to find out relationship between objective knowledge and subjective knowledge. The subjects of this study were female adults from theirs twenties to theirs forties who lived in Seoul, Kyunggi or Incheon areas and Quota sampling method was used age and areas. The data were obtained from 603 questionnaires. Data were statistically analyzed using SPSS 10 and major statistical methods are mean, frequency, Pearson correlation coefficient, and Cronbach's $\alpha$ coefficient. The results are as follows: 1. Objective knowledge consisted of the product knowledge, brand knowledge, purchase knowledge and usage knowledge, and subjective knowledge consisted of experience and self-evaluation knowledge. 2. Consumer knowledge was related to the subjective knowledge and objective knowledge. But, there was relatively a low relationship between subjective knowledge and objective knowledge of apparel.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.6
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• pp.13-19
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• 2004

This study was performed to evaluate permeable properties of eco-concrete using soil, natural coarse aggregate, soil compound and polypropylene fiber. The fIexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were increased with increasing the content of coarse aggregate, soil compound and polypropylene fiber. The flexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were 259 MPa, 3,527 m/s and 275 ${\times}$ 102 MPa at the curing age of 28 days, respectively. The coefficient of permeability was decreased with increasing the content of coarse aggregate and soil compound, but it was increased with increasing the content of polypropylene fiber. Accordingly, this concrete can be used for farm road.

• Journal of the Korean Home Economics Association
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• v.20 no.2
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• pp.135-140
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• 1982

As a step preliminary to the factor-analysis of a child-rearing attitude scale under construction, its preliminary form containing a total of 368 self-answered questions was administerd to 88 married women with one or more children in the grade school age. all graduates of colleges and in possession of a home telephone and a house, twice from one week apart. The test-retest correlation coefficients, calculated for each test item based on the subject's choice among the three response alternatives on two test ocasions, ranged from .80 to .10. The cut-off point of r=.41 or lower led to the elimination of 48 items. As a point of incidental interest, the rate of response concordance. The namber of subjects giving the same categroy response on two occasions was calculated for each item and it was correlated with its test. retest correlation coefficient. The two different indices of item test-retest reliability were found not related to each other. Empirical evidence, as well as rational justifications, was presented to show that the correlation coefficient is the better of the tow indices of item test-retest reliability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.87-91
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• 2009

Recycling demolished concrete as an alternative source of coarse aggregates for the production of new concrete can help solve the growing waste disposal crisis and the problem of depleted natural aggregates. The purpose of this study is to investigate chloride migration of recycled aggregate concrete containing pozzolanic materials by chloride migration coefficient. The specimens were made with recycled coarse aggregate as various replacement ratio(10, 30, 50%) and metakaolin, blast furnace slag, fly ash is replaced for recycled concrete with mixing ratio 20%. The major results are as follows. 1) Compressive strength of recycled aggregate concrete containing pozzolanic materials increase as curing age and chloride migration decrease. 2) When the replacement ratio of recycled coarse aggregate is 30%, the chloride migration coefficient of recycled concrete containing blast furnace slag, metakaolin shows the similar or lower value than plain concrete at all ages.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.549-552
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• 2006

Deicing salt has been generally used for prevention of a road freezing in winter, and the amount is increasing every year. However, deicing salt may induce the decrease of bond strength, surface scaling, and environmental pollution, etc. The purpose of this paper is to suggest the fundamental data on safety and durability for concrete structures through the estimation of characteristics of chloride penetration with deicer types. According to the test results, as age of concrete is increased, chloride penetration depth is also increased independent of deicer types. However, there is no remarkable difference between deicer types. And when the estimation of chloride diffusion is carried out by immersion test, diffusion coefficient is decreased with ages, and short-term estimation may overestimate the coefficient.

• Communications for Statistical Applications and Methods
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• v.12 no.2
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• pp.381-394
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• 2005

In order to estimate the damage of orchards due' to natural disasters such as typhoon, severe rain, freezing or frost, it is necessary to estimate the number of fruit bearing before and after the damage. To estimate the fruit bearing after the damages are easily done by delegations, but it cost too high to survey every insured farm household and calculate the fruit bearing before the damage. In this article, we suggest to use a random coefficient model to predict the numbers of fruit bearing in the orchards before the damage based on the tree age and the area information.

• Women's Health Nursing
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• v.12 no.3
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• pp.204-209
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• 2006

Purpose: The Edinbergh Postnatal Depression Scale (EPDS) has seen widespread use in epidemiological and clinical studies. The objective of this research was to translate and to test the reliability and validity of the 10-item EDPS in Korea. Methods: Subjects were 145 women who were 6 to 10 weeks post delivery. To test reliability, the internal consistency was assessed by Cronbach's alpha coefficient. Validity testing was performed using convergent validity by Pearson's correlation. Data was gathered at 3 hospitals during Oct. 2005 after obtaining an informed consent. Result: The mean age of the subjects was 29.9 years. and the mean parity was 1.46 times. The mean EPDS score was 18.4. Reliability analysis showed a satisfactory result (Cronbach's alpha coefficient=.84). There were significant positive correlations between EPDS and Mills postnatal depression and anxiety check list scores as expected(r=.69, p<.001) and thus supported convergent validity. Conclusion: The study findings showed that the Korean version of the EPDS-10 is a reliable and valid instrument that can be used for measuring postnatal depression in Korea.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.37-44
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• 1970

Human body volumes were calculated from the measurments of body height and body weight. Equations Suited to express the relations of height, weight, and surface area to show the body volume were derived from the body volume measurements by means of underwater. weighing method. Underwater body weights were corrected for the residual volume of long obtained by the Rahn's three breath method. Underwater weighing was performed on 173 male subjects aged between 13 and 51 years. Subjects were divided into 4 age groups, namely, 13-16 years group of 47 subjects, 16-19 years group of 46 subjects, adult group aged between 22 and 38 years comprising 45 subjects, and middle-aged group (40-51 years) of 35 subjects. The group division was made on .the basis of physical growth and development. The following results were obtained. 1. Body height (H, cm), body weight (W, kg), body surface area $S,\; m^{2})$, and body volume (V, liter.) interrelated closely. V/S showed a high correlation with W/H and the coefficient of correlation was r=0.97 irrespective of age group differences of the subjects. The coefficients of correlation between V/S and W/H in the total mate subjects as a single group was r=1.983. Subsequently the following regression equation was obtained. V = S X (54.84 W/H + 14.08) The agreement of body volume values obtained by the calculation and underwater weighing in the total subject group was better than that of the separate age group division. 2. The calculated values of body volume were: 40.4 l (euiqvalent to the body density value of 1.0562 kg/1) in 13-16 years group; 52.0 l (equivalent to density value of 1.0723 kg/l) in 16-19 years group; 55.3 l (equivalent to density value of 1.0570 kg/l) In the adult group; and 54. 0 l (equivalent to density value of 1.074 kg/l) in the middle-age group. The mean deviation of calculated from the measured volume value ranged between ${\pm}0.55$ and ${\pm}0.81$ liters. 3. The correlation between V/S and mean skinfold thickness of 4 sites (arm, back, iliac and chest) was high, namely, the coefficient of correlation was r=0.656. The coefficients of correlation between V./S and the $R\"{o}hrer$ index ranged between r=0.668 and r=0.810 affected by the difference in group age of the subject. The body volume (V) alone correlated poorly than V/S with mean skinfold thickness (r=0.606) and the $R\"{o}hrer$ index (r ranged between 0.274 and 0.588).