• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.17-27
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• 2011

A selection experiment for reduced residual feed intake (RFI) in Yorkshire pigs consisted of a line selected for lower RFI (LRFI) and a random control line (CTRL). Longitudinal measurements of daily feed intake (DFI) and body weight (BW) from generation 5 of this experiment were used. The objectives of this study were to evaluate the use of random regression (RR) and nonlinear mixed models to predict DFI and BW for individual pigs, accounting for the substantial missing information that characterizes these data, and to evaluate the effect of selection for RFI on BW and DFI curves. Forty RR models with different-order polynomials of age as fixed and random effects, and with homogeneous or heterogeneous residual variance by month of age, were fitted for both DFI and BW. Based on predicted residual sum of squares (PRESS) and residual diagnostics, the quadratic polynomial RR model was identified to be best, but with heterogeneous residual variance for DFI and homogeneous residual variance for BW. Compared to the simple quadratic and linear regression models for individual pigs, these RR models decreased PRESS by 1% and 2% for DFI and by 42% and 36% for BW on boars and gilts, respectively. Given the same number of random effects as the polynomial RR models, i.e., two for BW and one for DFI, the non-linear Gompertz model predicted better than the polynomial RR models but not as good as higher order polynomial RR models. After five generations of selection for reduced RFI, the LRFI line had a lower population curve for DFI and BW than the CTRL line, especially towards the end of the growth period.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.956-959
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• 2004

Recently the monitoring system of tool setting in high speed precision machining center is required for manufacturing products that have highly complex and small shape, high precision and high function. It is very important to reduce time to setup tool in order to improve the machining precision and the productivity and to protect the breakage of cutting tool as the shape of product is smaller and more complex. Generally, the combination of errors that geometrical clamping error of fixing tool at the spindle of machining tool and the asynchronized error of driving mechanism causes that the run-out of tool reaches to 3$^{\sim}$20 times of the thickness of cutting chip. And also the run-out is occurred by the misalignment between axis of tool shank and axis of spindle and spindle bearing in high speed rotation. Generally, high speed machining is considered when the rotating speed is more than 8,000 rpm. At that time, the life time of tool is reduced to about 50% and the roughness of machining surface is worse as the run-out is increased to 10 micron. The life time of tool could be increased by making monitoring of tool-setup easy, quick and precise in high speed machining tool. This means the consumption of tool is much more reduced. And also it reduces the manufacturing cost and increases the productivity by reducing the tool-setup time of operator. In this study, in order to establish the concept of tool-setup monitoring the measuring method of the geometrical error of tool system is studied when the spindle is stopped. And also the measuring method of run-out, dynamic error of tool system, is studied when the spindle is rotated in 8,000${\sim}$60,000 rpm. The dynamic phenomena of tool-setup are analyzed by implementing the monitoring system of rotating tool system and the non-contact measuring system of micro displacement in high speed.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.173-181
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• 1994

A Cold spot temperature control system for the batch annealing furnace has been estabilished in order to reduce energy consumption to improve productivity and stabilize the propertics of products. Therefore we confirmed a relation between annealing cycle time and atmospheric gas, variation of coil cold spot temperature with time during heating and actual temperature measurements at mid-width of each coil during heating and actual temperature measurements at mid-width of each coil during soaking. The results of the tempaeature variation effect on the batch annealing are as follows. 1) Heating time is reduced to one half with increasing atmospheric gas flow rate and changing of atmospheric gas component from HNx to Ax gas, and annealing cycle time is reduced to 2.7 times. 2) In case of short time healing, the slowest heating part is the center of B coil, in case of long time heating, the low temperature point moves from the center of coil to inside coil. And the temperature in this part is higher than other parts when cooling. When finished heating, the cold spot is located 1/3 of coil inside in case of HNx atmospheric gas. But center of coil in case of Ax atmospheric gas. 3) The outside of top coil is the highest temperature point when heating, which becomes the lowest temperature point when cooling. So, this point becomes high temperature zone at heating and low temperature zone at cooling, It has relation according to atmospheric gas component and flow rate. 4) Soaking time at batch annealing cycle determination is made a decision by the input coil width, and soaking time for quality homogenization of 1214mm width coil must be 2.5 hours longer than that of 914mm width coil for the same ciol weight. 5) Annealing cycle time with Ax atmospheric gas is extended 1 hour in of slow cooling during 5 hours in order to avoid rapid cooling.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• International Journal of Quality Innovation
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• v.9 no.3
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• pp.71-91
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• 2008

The definition of cycle time is the time from the wafer start to the wafer output. It usually takes one or two months to get the product since customer decides to produce it. The cycle time is a critical factor for customer satisfaction because it represents the response time to the market. Long cycle time reflects the ineffective investment for the capital. The cycle time is very important for foundry because long cycle time will cause customer unsatisfied and the order loss. Consequently, all of the foundries put lots of human source in the cycle time improvement. Usually, we make decisions based on the experience in the cycle time management. We have no mechanism or theory for cycle time management. We do work-in-process (WIP) management based on turn rate and standard WIP (STD WIP) set by experiences. But the experience didn't mean the optimal solution, when the situation changed, the cycle time or the standard WIP will also be changed. The experience will not always be applicable. If we only have the experience and no mechanism, management will not be work out. After interview several foundry fab managers, all of the fab can't reflect the situation. That is, all of them will have an impact period after product mix or utilization varied. In this study, we want to develop a formula for standard WIP and use statistical process control (SPC) concept to set WIP upper/lower limit level. When WIP exceed the limit level, it will trigger action plans to compensate WIP Profile. If WIP Profile balances, we don't need too much WIP. So WIP level could be reduced and cycle time also could be reduced.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.121-126
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• 2013

Cycloconverter used as a power conversion device in the speed and torque control system of AC machines has the advantage of a simple control and a large torque at low speed. In addition, because a rectifier, a DC link, and an inverter are not installed, this system is simple and suitable for large power system. If a power conversion device, which is currently used as a propulsion motor of large vessel, is changed into cycloconverter, the system is simplified and then the installation costs can be significantly reduced. However, conventional cycloconverter has the increased harmonics because the power loss is large and the waveform of output voltage is distorted, due to the high-speed switching of power semiconductor devices. In order to improve these shortcomings, this paper describes a phase shifting filter which is composed of two inputs with different phases in the primary side and one output in the secondary one. As the voltage waveforms with two different phases are added and transformed into the secondary side, these outputs are close to sinusoidal waves. Thereby the voltage waveforms, which are applied to the propulsion motors, are improved and total harmonic distortions (THDs) are significantly reduced.

• Korean journal of applied entomology
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• v.9 no.2
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• pp.75-80
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• 1970

1. Retention of fungicides and efect of the mixing of spreaders and insecticides with fungicides in control of apple bitter rot were evaluated by 'the assay of inhibition zones with apple exocarp disks:' 2. The effectiveness of chemicals was reduced gradually as the time after treatment increased. Of all the chemicals tested, Difolatan retained approximately 60 percent of the original activity even after IS days. Difolatan had the highest followed by Tuzet, Phaltan, Bordeaux mixture, and Delan, in that order. 3. The fungicidal acivity of Tuzet decreased with increasing application of simulated rain. The wash-offf of Tuzet was reduced by adding spreaders. Dry skim milk and soybean extract were better than commercial chemicals such as Lino No. 1,2 and Tween 20. 4. The mixing of insecticides such as EPN, Folithion, Parathion and Lebaycid with Phaltan resulted in no significant differences in fungicidal effect even after 12 days of storage at room temperature.

• Journal of Life Science
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• v.11 no.2
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• pp.144-152
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• 2001

In order to improve functionality of kochujang which is one of the traditional foods of Korea, sea tangle powder(2, 4, 6 and 8% sea tangle powder on the glutinous rice weight basis) was added to the raw material of kochujang and then investigated the change of physiochemical properties with control kochujang during the fermentation at 3$0^{\circ}C$ for 120 days. During 120 days fermentation, moisture and crude protein contents were gradually decreased with fermentation time, whereas crude fat content NaCl were slightly increased with fermentation time. The contents of reducing sugar of sea tangle kochujang was rapidly increased until 60 days of fermentation after that it was increased slightly up to 90 days of fermentation to the highest value and then reduced slightly or not changed approximately until 120 days. pH was reduced up to 60 days of fermentation after that it remained 4.63~4.91 in 90~120 days. Acidity was increased with fermentation time, and it was the highest value of 11.5~12.4$m\ell$ in 120 days of fermentation. Viscosity was increased with increased with fermentation time. Especially a case of additional sample of 8% sea tangle powder was highly increased until 60 days. A case of color difference value, in initial time of preparation of kochujang was distinct difference of value for additional samples respectively but as the fermentation progressed, among the samples not found consistent change of color difference value. L value was gradually decreased during fermentation. A value was decreased up to 30 days of fermentation and it was increased again totally at 60 days of fermentation. B value was decreased totally at initial time of fermentation and a case of control was increased again at 90 days of fermentation, the other samples increased again 60 days earlier than 30 days.

• Korean Journal of Health Education and Promotion
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• v.21 no.3
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• pp.87-100
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• 2004

Objective: This research has been conducted in order to conduct sex education using information and communication technologies (ICT) which is currently taught to elementary school students, understand how this method of education affects the knowledge of and attitude towards sexual health in them, so that it could be actually applied in classrooms. Subject: 115 students were divided into three different groups: a comparison group of 38 students (who were given no sex education at all), control 2 group of 39 students (who were given sex education via video programmes), and control 1 group of 38 students (who were given sex education using ICT). Research Tool: A questionnaire used by the literature studies. After verifying content validity, it was modified and supplemented in this way: sex knowledge was reduced to 26, and sex attitude was also reduced to 11. The reliability of the research tool was Cronbach's a=0.86 for sex knowledge tool, and Cronbach's a=0.81 for sex attitude tool. The collected data have been analysed using SPSS 11.0 program. The content validity was analysed by factor analysis and multiple regression analysis, and hypothesis verification was analysed using repeated measure ANOVA test. Result: 1) In sex knowledge marks, there was a significant difference according to the group (p=.009) and point of time (p=.000), and there was a significant interaction between the groups and point of time(P=.000). As a result, it turned out that both video programmes and ICT were significantly effective in improve the knowledge. 2) In sex attitude marks, there were no significant differences according to the group (p=.213), but there was a significant difference according to point of time (p=.002), and there was a significant interaction between the groups and point of time(P=.018). As a result, it turned out that only the education method using ICT was effective in improving the attitude. Conclusion: From the results of this research, it can be said that the sex education using ICT was the most effective method in improving the sex knowledge and attitude of students at elementary school. Therefore, it is advisable that the sex education methods using ICT should be developed and applied continuously.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.113-118
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• 1979

In the soil treated with irrigation control and gypsum, different species of rice plants, Jin-heung, Aggibare, Tong-il, Mil-yang 23, Noindo, Yugnong-chat, were grown. The content of cadmium, copper and zinc in the brown rice was investigated. Results obtained are as follows : 1) Cadmium Content of brown rice was remarkably reduced under the condition to maintain the reduction than oxidation after ear forming stage, and also the application of gypsum was additional effects to reduce cadmium uptake under reduction condition. Zinc and copper contents in the brown rice was similar to calcium reducing, but their effects of reduction were appeared less than cadmium. 2) The reduced tendency of cadmium uptake under the reduction condition was in the order of Tong-il>Mil-yang23>Aggibare>Yugnong-chal>Noindo>Jin-heung. 3) In the oxidzing condition, Jin-heung uptaked cadmium, copper and zinc more than any other species.