• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.23-27
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• 1997

This paper introduces the structural design optimization of a high speed machining center using multi-step optimization combined with G.A.(Genetic Algorithm) and Weighted Method. In this case, the design problem is to find out the best design variables which minimize the static compliance, the dynamic compliance, and the weight of the machine structure simultaneously. Dimensional thicknesses of the thirteen structural members of the machine structure are adopted as design variables. The first step is the cross-section configuration optimization, in which the area moment of inertia of the cross-section for each structural member is maximized while its area is kept constant The second step is a static design optimization, In which the static compliance and the weight of the machine structure are minimized under some dimensional and safety constraints. The third step IS a dynamic design optimization, where the dynamic compliance and the structure weight are minimized under the same constraints. After optunization, static and dynamic compliances were reduced to 62.3% and 95.7% Eorn the initial design, while the weight of the moving bodies are also in the feaslble range.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.504-509
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• 2003

In this paper, a multi-step optimization using a G.A.(Genetic Algorithm) with variable penalty function is introduced to the structural design optimization of a high speed machining center. The design problem, in this case, is to find out the best cross-section shapes and dimensions of structural members which minimize the static compliance, the dynamic compliance, and the weight of the machine structure simultaneously. The first step is the cross-section shape optimization, in which only the section members are selected to survive whose cross-section area have above a critical value. The second step is a static design optimization, in which the static compliance and the weight of the machine structure are minimized under some dimensional constraints and deflection limits. The third step is a dynamic design optimization, where the dynamic compliance and the structure weight are minimized under the same constraints as those of the second step. The proposed design optimization method was successful applied to the machining center structural design optimization. As a result, static and dynamic compliances were reduced to 16% and 53% respectively from the initial design, while the weight of the structure are also reduced slightly.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.103-111
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• 1987

Understanding grain filling characteristics represented by grain filling duration and grain filling rate is import-ant in improving higher yielding varieties and developing better cultural methods of rice (Oryza sativa L.). Recently developed 6 Japonica and 6 Japonica/Indica varieties were grown under 3 nitrogen levels at Experimental Farm of Chungbuk National University in 1986. The range of grain filling duration of 12 varieties was 20.9-39.0 days, while grain filling rate ranged from 53.8 to 136.6 mg. panicle$^{-1}$. day$^{-1}$. Although the difference of the average grain filling duration between Japonica varieties and Japonica/Indica was less than 4 days, the average grain filling rate of Japonica/lndica varieties was greater than Japonica more than 30%. Samgangbyeo showed the shortest grain filling duration of 21.0-24.2 days and the greatest grain filling rate of 119.3-143.8 mgㆍpanicle$^{-1}$. day$^{-1}$ under 3 nitrogen levels, while Seomjinbyeo and Milyang 23 showed the quite opposite grain filling characteristics. Nitrogen levels did not show any significant effects on grain filling characteristics. Negative correlation was round between grain filling duration and grain filling rate, and significant positive correlations of grain filling rate with grains/panicle, grain weight and panicle weight indicated that grain filling rate is more important characteristics of grain filling. Pathway analysis revealed that contribution of grain filling rate to panicle weight is rather indirect through grain weight.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.112-121
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• 2005

This paper is concerned with smooth trajectory generation of biped robot which has inverted pendulum type balancing weight. Genetic algorithm is used to generate the trajectory of the leg and balancing weight. Balancing trajectory can be determined by solving the second order differential equation under the condition that the reference ZMP (Zero moment point) is settled. Reference ZMP effect on gait pattern absolutely but the problem is how to determine the reference ZMP. Genetic algorithm can find optimal solution under the high order nonlinear situation. Optimal trajectory is generated when use genetic algorithm which has some genes and a fitness function. In this paper, minimization of balancing joints motion is used for the fitness function and set the weight factor of the two balancing joints at the fitness function. Inverted pendulum type balancing weight is very similar with human and this model can be used fur humanoid robot. Simulation results show ZMP trajectory and the walking experiment made on the real biped robot IWR-IV.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.109-116
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• 2007

The purpose of this paper is to evaluate the fire resistant performances of load-bearing wall using both composite and steel stud panel infilled with light-weight formed mortar under axial loading according to KS F 2257(1999). The minimum requirement of 2 hours fire resistant rating is needed for the residential and commercial buildings under the fire regulation of Korea. From test results, it is found that two types of specimen composed of the hybrid stud and steel stud panel filled with light-weight formed mortar fited in with the requirement of 2 hours fire resisting rate for the load-bearing wall. In the conclusions, the specimen with hybrid stud shows predominating fire-resistant performance on the adiabatic effects rather than that of the steel stud specimen.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.391-397
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• 2021

One of the sustainable development goals is to promote good health and well-being for all people. Child health is a top priority since their health issues can have a detrimental impact on human capital development, which is a critical input for the growth model. This paper applies the health production model to explore the determinants that influence the health of children under the age of five. The results of a survey of 203 households in Ho Chi Minh City, Vietnam, were examined. Child health is measured using anthropometric indicators such as weight-for-age, height-for-age, and weight-for-height (ZWFH). Three separate multinomial logistic models are regressed to examine the drivers of child health as proxied by z-score weight for age, z-score height for age, and z-score weight for height. The significance of input variables relating to a child's attributes, household, and environment was validated by the findings. The inclusion of overweight besides under-nourished indexes is novel because it reflects the current trend of child over-nutrition. The findings of the study highlight the importance of a wide range of initiatives to enhance child health. Moreover, the genetic effect is found to be crowded out by environmental and household factors. The finding verifies that despite their parents' moderate height, the future generation of Vietnamese can achieve the desired height.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.767-772
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• 2003

The clay which transported into a pond under the high water content condition have no effective stress which develop from the starting point of sedimentation and self-weight consolidation. Since sedimentation and self-weight consolidation dependent on self-weight of solids is made progress over a long time, to accelerating it have many advantages in the economic view In this paper, sand spreading method which is one of sedimentation and self-weight consolidation acceleration method is studied through a series of experiments considering the mixing ratio of sand and clay. The test results show that the mixing ratio of clay and sand of 1:0.2 is the biggest rate of consolidation and the pouring at the end point of sedimentation considerably effects on consolidation rate.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.31-36
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• 2013

For lighting of dark and hazardous workplace such as compartment of ships under construction, workers should use hand lamps of explosion-proof type. However, the heavy weight of such lamps has prevented most impatient workers from using such types of lamps extensively. In this paper, we developed a light weight hand lamp of intrinsic safety type which reduced the weight a lot while maintaining or improving the lighting and explosion-proof function. We made a prototype which consisted of lamp fixture and high frequency power supply. Testing results show that the hand lamp meets well all the explosion-proof testing requirements of the Korea Occupational Safety and Health Agency. And more, we surveyed the explosion protection technology of a light weight hand lamp, and suggested the advantage/disadvantage to apply lighting of hand lamp about economical aspect.

• Journal of the Korean Society of Clothing and Textiles
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• v.8 no.3
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• pp.73-79
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• 1984

The purpose of the study is to obtain the basic data of the proper clothing weight according to the subcutaneous fat thickness. This study was done in April and October, and the subjects were 295 male and female college students. Results were as follows: 1. In the case of female students in April, there was no correlation between the subcutaneous fat thickness and the total clothing weight. But there was low negative correlation between the subcutaneous fat thickness and the upper and under clothing weight. 2. In the case of female students in October, there was low negative correlation between the subcutaneous fat thickness and the total, upper, outer clothing weight. 3. In the case of male students in October, there was no correlation between the subcutaneous fat thickness ana the clothing weight.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.843-845
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• 1999

To evaluate direct and maternal effects on calf market weight (CMW) and carcass weight (CW) in Japanese Black cattle under an animal model, genetic parameters were estimated using 51,320 records of CMW and 11,944 records of CW, respectively. Direct and maternal heritabilities, and direct-maternal genetic correlation were estimated to be 0.22, 0.06 and 0.27 for CMW, and 0.23, 0.12 and -0.40 for CW, respectively. Correlation coefficient between maternal breeding values for CMW and CW was 0.521 for 157 sires appeared in both CMW and CW data sets. These results suggest that the maternal genetic effect on pre-weaning growth carries over to carcass weight. Maternal breeding values for both calf market weight and carcass weight could be used as the indicator traits of maternal ability in Japanese Black cattle.