• Advances in concrete construction
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• v.1 no.1
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• pp.85-102
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• 2013

Prior concrete strength distributions can be updated by using direct information from test results as well as by taking into account indirect information due to conformity control. Due to the filtering effect of conformity control, the distribution of the material property in the accepted inspected lots will have lower fraction defectives in comparison to the distribution of the entire production (before or without inspection). A methodology is presented to quantify this influence in a Bayesian framework based on prior knowledge with respect to the hyperparameters of concrete strength distributions. An algorithm is presented in order to update prior distributions through numerical integration, taking into account the operating characteristic of the applied conformity criteria, calculated based on Monte Carlo simulations. Different examples are given to derive suitable hyperparameters for incoming strength distributions of concrete offered for conformity assessment, using updated available prior information, maximum-likelihood estimators or a bootstrap procedure. Furthermore, the updating procedure based on direct as well as indirect information obtained by conformity assessment is illustrated and used to quantify the filtering effect of conformity criteria on concrete strength distributions in case of a specific set of conformity criteria.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.2
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• pp.301-315
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• 2000

The main purpose of this study was to evaluate the effect of a Rhythmical Exercise Program(REP) on physiological functions such as muscle strength, blood pressure, pulse, flexibility and body fat in the elderly. The research employed a non-equivalent control group pre-post test quasi experimental design. REP consisted of 45 minutes of dance, 3 times a week for 10 weeks. The formulated hypothesis were examined using the non-parametric statistics; Wilcoxon Signed rank sum test and Mann-Whitney test. The results are as follows; 1. The upper muscle strength and lower muscle strength of the experimental group were significantly higher than those of the control group following the REP(P<.0 5). And the Period of REP affected the muscle strength; the longer the exercise period, the stronger the muscle strength became. 2. The systolic blood pressure of the experimental group was significantly lower than that of the control group following the REP(p<.05). But there was no significant difference in the diastolic blood pressure between the experimental and control groups. The period of REP affected only systolic pressure; the longer the exercise period, the lower the systolic pressure became. 3. There was no significant difference in heart rate between the experimental and control groups, following the exercise period. 4. The flexibility of the experimental group was significantly higher than those of the control group following the REP(p<.01). And the period of REP affected flexibility; the longer the exercise period, the higher the flexibility(p<.05) became. 5. There was no significant difference of body fat between the experimental and control groups. The body fat of the experimental groups was significantly lower only 10 weeks after exercise(p<.01). Based on these results, it is suggested that rhythmical exercise program improves muscle strength, systolic pressure, and flexibility in the elderly.

• Proceedings of the Korea Concrete Institute Conference
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• 1990.10a
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• pp.101-106
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• 1990

To estimate the concrete strength at fresh state is very important problem in quality control. So, this study is designed for analyzing the quality control application of practical use Re-Mi-Con with the early estimation method of concrete strength using the test of solution heat of hydrochloric acid.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.176-177
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• 2019

Recently, efforts are made to apply 200MPa levels of ultra-high strength concrete to structures exceeding 40MPa.. Ultra-high strength concrete has been steadily researched in Korea as well as abroad, and now it is equipped with 200MPa ultra-high strength concrete mixing technology. Because ultra-high strength concrete has a higher range of compressive strength than ordinary concrete, it is difficult to accurately measure the compressive strength of UHPC concrete with existing compressive strength measuring equipment and can be less reliable. In this study, the compressive strength of the SC80 was measured according to the test method to compare the compressive strength of the SC80 by applying various methods of measurement of compressive strength. The compressive strength test method measured the compressive strength according to the size of the specimen, the grinding method, and the capacity of the UTM equipment.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.357-362
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• 1996

The objective of this study is to investigate material properties and quality control of cast-in-place high strength concrete. High strength concrete with a design strength of 420 kgf/$\textrm{cm}^2$ is successfully produced at a ready-mixed concrete plant, and placed at a tall building. Many laboratory and field tests are carried out for the successful construction of the reinforced high strength concrete building. As the results of this study, the average actual 28-day compressive strength is 513 kgf/$\textrm{cm}^2$ and the coefficient of variation is 6.8%. The placing speed is comparable to normal strength concrete, however, the pump pressure is higher than that of normal strength concrete. To prevent cracks of massive and long concrete members, the control of hydration heat and shrinkage is very important.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.4
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• pp.382-387
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• 2011

In this paper, a LBCC (Latter Bank Cooling Control) for the high strength steel is proposed to obtain the desirable temperature and the property of the material along the longitudinal direction of the steel on the ROT (Run-Out Table) process. A cooling valve is modeled to analyze the response of the ROT banks. The control concept is derived from a field data, a valve model considering the valve response and a TTT (Time-Temperature Transformation) diagram. The proposed control is verified from the simulation results under the various carbon quantities. It is shown through the field test of the hot strip mill that the deviation of the CT (Coiling Temperature) is considerably decreased by the proposed temperature control.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.579-584
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• 2001

The purpose of this study was to determine the effects of kinesio taping on lumbar muscle strength and flexibility. The samples for this study were 61 normal subjects(35 experimental group, 26 control group), aged 19 to 29 years. The data were analyzed by paired t-test. pearson and bivariate correlations. The results of this study were as follows : 1. The lumbar muscle strength was significant change in the experimental group(p<0.05). 2. The lumbar muscle strength was no significant change in the control group(p>0.05). 3. The flexibility was significant change in the experimental group and control group(p<0.05). 4. The lumbar muscle strength and flexibility were high associated in between session reliability(p<0.05).

• Advances in concrete construction
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• v.10 no.1
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• pp.21-34
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• 2020

Precast deck joints have larger crack width than cast-in-place concrete decks. The initial crack typically occurs at the maximum moment but cracks on precast joints are significant and lead to failure of the deck. The present crack equation is applied to cast-in-place decks, and requires correction to calculate the crack width of precast deck joints. This research aims to study the crack width correction equation of precast decks by performing static tests using high strength and normal strength concrete. Based on experimental results, the bending strength of the structural connections of the current precast deck is satisfied. However it is not suitable to calculate and control the crack width of precast loop connections using the current design equation. A crack width calculation equation is proposed for crack control of precast deck loop joints. Also included in this paper are recommendations to improve the crack control of loop connections.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.165-170
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• 2015

In this paper, The strength and driving characteristics of it were investigated according to developing the traction motor for 8200 electric locomotive series. For this purpose, Flux density strength was analyzed and then structural strength was investigated such as a stator frame, design of the rotor shaft bearing according to the design process. In addition, the traction motor operating point was analyzed according to slip frequency variation at a power source frequency. As the results of analysis on torque-speed characteristic curve, we was confirmed that traction motor was controlled as torque control prior to motor speed 1610[rpm], power control between 1610[rpm] and 2500[rpm] and breakdown torque control more than motor speed 2500[rpm].

• Journal of Families and Better Life
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• v.27 no.5
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• pp.123-135
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• 2009

The purpose of this study was to investigate the effects of family conflict and self-control on school maladjustments of early adolescents. Subjects of this study consisted 662 middle school students drawn from 4 middle schools in Cheong-ju city. The results of this study were as follows: First, younger students' maladjustment to teachers was influenced by variables such as school year, economic levels, conflict strength between parents, conflict settlement between parents, reliability between parents and children, communication between parents and children and self-control, etc. In other words, students' maladjustment to teachers was high at the students in the 2nd year rather than in the 1st year, low economic level, high conflict strength between parents that younger students perceived, low conflict settlement between parents, low reliability between parents and children, high hostility between parents and children and low self-control. Second, younger students' maladjustment to the class was influenced by variables such as gender, school year, economic levels, conflict strength between parents, reliability between parents and children, communication between parents and children, and self-control, etc. In other words, young students' maladjustment to the class was high at the 2nd year students rather than at the 1st year students, low economic level, high conflict strength between parents, low reliability between parents and children, poor communication between parents and children, and low self-control. Third, younger students' maladjustment to rules was influenced by variables such as school year, economic level, conflict level between parents, hostility between parents and children, and self-control, etc. In other words, younger students' maladjustment to rules was high at the 1st year students rather than the 2nd year students of middle school, low economic level, high conflict strength between parents, high hospitality between parents and children and low self-control, etc. Fourth, younger students' maladjustment to friends was influenced by variables such as conflict strength between parents, conflict settlement between parents, hospitality between parents and children, and self-control, etc. In other words, younger students' maladjustment to friends was high at high conflict strength between parents, low conflict settlement between parents, high hospitality between parents and children and low self-control, etc. In the study, self-control was found to be the most important variable at younger students' maladjustment to teachers, class and rules, etc, and conflict settlement between parents was found to be the most significant variable at younger students' maladjustment to friends.