• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.3
• /
• pp.402-407
• /
• 2013

In this paper, the image processing for flexible disk grinding and the effect of the grinding conditions on the flat zone length of a workpiece are investigated, with the purpose of automating the grinding process. To accomplish this, three issues should be carefully studied. The first is finding the relationship between the flat zone length and the grinding conditions such as the cutting speed and feeding speed. The second is developing a neural network algorithm to predict the flat zone. The third is developing an image processing algorithm to measure the flat zone length of a workpiece. Slope analysis is used to determine straight and curved sections during the image processing. For verification, the estimated length and the length from the image processing are compared with the length measured by a projector. There is a minimum difference of 1.7% between the predicted and measured values. The results of this paper will be useful in compiling a database for process automation.

• Structural Engineering and Mechanics
• /
• v.26 no.2
• /
• pp.211-229
• /
• 2007

An experimental investigation to determine the transfer length of a seven-wire prestressing strand in different concretes is presented in this paper. A testing technique based on the analysis of bond behaviour by means of measuring the force supported by the prestressing strand on a series of specimens with different embedment lengths has been used. An analytical bond model to calculate the transfer length from an inelastic bond stress distribution along the transfer length has been obtained. A relationship between the plastic bond stress for transfer length and the concrete compressive strength at the time of prestress transfer has been found. An equation to predict the average and both the lower bound and the upper bound values of transfer length is proposed. The experimental results have not only been compared with the theoretical prediction from proposed equations in the literature, but also with experimental results obtained by several researchers.

• Journal of the Korean Wood Science and Technology
• /
• v.23 no.4
• /
• pp.46-53
• /
• 1995

The anatomy of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens was described and analyzed. Sixteen wood anatomical characters, habit and phenology factors were determined by simple correlation and principal component analysis. Strong positive correlations were found between vessel element length and fiber length, ray width and ray height, simple pits of fiber wall and paratracheal parenchyma distribution. The results of principal component analysis (PCA) disclose the primitive characteristics and the direction of xylem evolution of Korean diffuse-porous woods. The xylem evolution scenario for Korean dicotyledonous woods is considered to be developed in the direction of decreasing trends of vessel frequency, vessel element length, and length/diameter(L/D) ratio of vessel element but increasing trends of vessel diameter, fiber length/vessel element length(F/V) ratio, libriform wood fibers, simple perforation, and homogeneous ray composition. Increase of vessel diameter and decrease of vessel frequency seem to be related to the improvement of conductive efficiency, and increase of the vessel element length and occurrence of scalariform perforation in vessel element may be related to enhanced of conductive safety. Also the libriform wood fibers and ray features appear to have relationship with mechanical support and nutrient metabolism, respectively.

• Structural Engineering and Mechanics
• /
• v.76 no.1
• /
• pp.67-81
• /
• 2020

Pretensioned concrete (PC) is widely used in contemporary construction. Bond of prestressing strand is significant for composite-action between the strand and concrete in the transfer and flexural-bond zones of PC members. This study develops a new methodology for quantifying the bond of 18-mm prestressing strand in PC members based on results of a pullout test, the Standard Test for Strand Bond (STSB). The experimental program includes: (a) twenty-four pretensioned concrete beams, using a wide range of concrete compressive strength; and (b) twelve untensioned pullout specimens. By testing beams, the transfer length, flexural-bond length, and development length were all measured. In the STSB, the pullout forces for the strands were measured. Experimental results indicate a significant relationship between the bond of prestressing strand to the code-established design parameters, such as transfer length and development length. However, the code-predictions can be unconservative for the prestressing strands having a low STSB pullout force. Three simplified bond equations are proposed for the design applications of PC members.

• Journal of Korean Physical Therapy Science
• /
• v.18 no.1
• /
• pp.51-60
• /
• 2011

Purpose: The purpose of this study was to investigate hamstring length during static uprighting position using weight distribution ratio. Methods: Ninety-six volunteers(56 males) were participated. The active knee extension test(AKE) was measured 3 times on both legs. The mean score of AKE was obtained. Then, the measurement of weight distribution ratio was observed 3 times on both legs, and its mean value was also calculated. Subjects were divided four groups based on their hamstring length measurement; both hamstring shortening group, left hamstring shortening group, right hamstring shortening group and normal hamstring length group. One-way ANOVA was employed to analyse collected data. Pearson's correlation was also hired to see any relationship between the hamstring length and the weight distribution. Results: In anterior/left area and posterior/right area, both hamstring shortening group left hamstring shortening group were superior to right hamstring shortening group and normal hamstring length group. Significant difference was existed statistically(p<.05) between groups. The correlation analysis between hamstring length and weight distribution ratio has not been shown any significant findings(Pant/post=0.733, Plt/rt=0.135). Conclusion: The results of the study may be applied to therapeutic management in posture and movement skill in musculoskeletal physical therapy.

• Journal of Korean Academy of Nursing
• /
• v.12 no.2
• /
• pp.31-44
• /
• 1982

The purpose of this study was to analyze the relationship between maternal attachment and discharge against advice in high risk infants and determine the factors which affect discharge against advice. Data of this study were collected by means of reviewing the medical records of 127 in-patients who were diagnosed as high risk infants in admission and interviewing of the mothers of these patients was done by telephone. The high risk categories were neonatal hyperbilirubinemia, congenital anomaly, congenital heart disease, blood disorder, neonatal infection and birth injury. Maternal attachment was measured by deviding the subjects into 2 groups, the one the continuing treatment group and the other the discharge against advice group. Maternal attachment is determined by an interplay of maternal attitude and specific infant behaviors. Maternal attachment developes through continuous physical and psychological contact between mother and infants. Later it developes into maternal love. The results were as follows: 1. There was a significant association between maternal attachment and discharge against advice, that is, the attachment score was higher in the continuing treatment group. 2. Inspite of controlling medical insurance, severity of disease and the length of stay, it was found that there continued to be either a partially significant or fully significant relationship between maternal attachment and discharge against advice. Stepwise multiple regression revealed that maternal attachment was second in importance as a predictor of discharge against advice, which indicates that maternal attachment was a significant predictor of discharge against advice. 3. Stepwise multiple regression revealed that in 32.3％ of these cases the significant predictors of discharge against advice were length of stay, maternal attachment, delivery type, feeding type and income.

• Korean Journal of Applied Biomechanics
• /
• v.28 no.3
• /
• pp.159-164
• /
• 2018

Objective: The aims of this study were to determine the impact peak force and kinematic variables in running speed and investigate the relationship between them. Method: Thirty-nine male heel strike runners ($mean\;age=21.7{\pm}1.6y$, $mean\;mass=72.5{\pm}8.7kg$, $mean\;height=176.6{\pm}6.1cm$) were recruited in this investigation. The impact peak forces during treadmill running were assessed, and the kinematic variables were computed using three-dimensional data collected using eight infrared cameras (Oqus 300, Qualisys, Sweden). One-way analysis of variance ANOVAwas used to investigate the influence of the running speed on the parameters, and Pearson's partial correlation was used to investigate the relationship between the impact peak force and kinematic variables. Results: The running speed affected the impact peak force, stride length, stride frequency, and kinematic variables during the stride phase and the foot angle at heel contact; however, it did not affect the ankle and knee joint angles in the sagittal plane at heel contact. No significant correlation was noted between the impact peak force and kinematic variables in constantrunning speed. Conclusion: Increasing ankle and knee joint angles at heel contact may not be related to the mechanism behind reducing the impact peak force during treadmill running at constant speed.

• Korean Journal of Applied Biomechanics
• /
• v.24 no.3
• /
• pp.259-267
• /
• 2014

The purpose of this study was to find the relationship between standing posture biomechanics and physical fitness in the elderly. Physical fitness variables and postural variables for 227 (140 women and 87 men) elderly individuals were tested. Physical fitness tests (Korean Institute of Sports Science, 2012) included 3m sit, walk, and return, grip test, 30 second chair sit and stand, sit and reach, figure 8 walks, and 2 minute stationary march. Postural biomechanics variables included resting calcaneal stance position (RCSP), shoulder slope, pelvic slope, knee flexion angle, leg length difference, thoracic angle, and upper body slope. In statistical analysis, multiple regression was conducted by using stepwise selection method via SAS (version 9.2). Analysis for both men and women revealed significant relationships between physical fitness and age, upper body slope, knee flexion angle, leg length difference. Pelvic and thoracic angle were only related to figure 8 walking and sit and reach in women, while RCSP and shoulder slope had no relationship with any physical fitness variables.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.1 s.149
• /
• pp.83-93
• /
• 2006

The purpose of this study is to analyze the relationship among subjective textures, sensibilities and objective handle of knit fabrics and to provide useful information in planning and designing knit fabrics. We made 20 plain knit fabrics, as specimens, with a combination of 5 kinds of wool/rayon fiber contents and 4 kinds of stitch loop length. For the subjective evaluation, we used 29 questions of subjective textures and sensibilities and employed statistical analysis tools such as factor, Pearson's correlation analysis. An objective handle was measured by Kawabata evaluation system and HV and THV was calculated by KN-402-KT and KN-301-winter. The analysis of a Pearson's correlation with objective properties and handles and structural properties of knit fabrics demonstrated a highly linear relationship. Especially, wool/rayon contents and WT of tensile properties and loop stitch length and G of shear properties showed a correlation coefficient over 0.9. But a relationship of objective properties and subjective textures and sensibilities was non-linear and a linear multi-regression analysis showed that a objective handle had a lower prediction power in the area of subjective textures and sensibilities.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.05a
• /
• pp.164-164
• /
• 1999