• Journal of the Ergonomics Society of Korea
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• v.16 no.2
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• pp.29-38
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• 1997

The research on the factors which effect on legibility is mainly utilized as the basic data of selecting the standard guideline of VDT screen. But the research on Korean is scarcer than that of English. Furthermore, it is unreasonable to apply the results of the foreign language to Korean, beause of the difference between the typography of English and that of Korean. Therefore, more systematic and ergonomic research of the Korean typography on VDT screen is needed. In this paper, an experimental study on search speed and error rate is designed and performed according to different Korean letter size and font on search task with VDT. The experimental screen based on popular Ming and Gothic style is made up of total 12 artificial screens, each 6 different font size. As the criteria of the performance, searching speed(s.s.) and error rate (e) are selected, and CFF value is measured to evaluate user's visual fatigue. The results of experiment in font show that the Korean Gothic style is superior to the Korean Ming style in user's visual performance. The letter size that gives user the optimal performance ranges from the visual angle 39.8' to 55.5' in Ming style, from the visual angle 39.8' to 52.6' in Gothic systle. In visual fatigue experiment, the better performance of letter size is, the less tired user feels. And the smaller letter size is, the more tired user feels. There is no relationship between font and user's visual fatigue.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.90-103
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• 2018

This paper presents the development of two ANN models which can predict an optimum production rate by controlling choke size in oil well, and gas injection rate in gas-lift well. The input data was solution gas-oil ratio, water cut, reservoir pressure, and choke size or gas injection rate. The output data was wellhead pressure and production rate. Firstly, a range of each parameters was decided by conducting sensitive analysis of input data for onshore oil well. In addition, 1,715 sets training data for choke size decision model and 1,225 sets for gas injection rate decision model were generated by nodal analysis. From the results of comparing between the nodal analysis and the ANN on the same reservoir system showed that the correlation factors were very high(>0.99). Mean absolute error of wellhead pressure and oil production rate was 0.55%, 1.05% with the choke size model, respectively. And the gas injection rate model showed the errors of 1.23%, 2.67%. It was found that the developed models had been highly accurate.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.3
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• pp.267-273
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• 2001

In this study, the survival rate of fiber is investigated by nozzle size difference in injection/mold sides. The survival rate of fiber is influenced about the nozzle size differ. Also, The mechanical properties of short carbon glass fiber reinforced polypropylene are experimentally measured as functions of fiber volume fraction and nozzle size difference. These mechanical properties are compared with the survival rate of fiber and fiber volume fraction using image analysis after pyrolytic decomposition. The survival rate of fiber as well as fiber volume fraction is influenced by injection processing condition, the used materials, mold conditions and nozzle sides difference, etc, In particular, the survival rate of fiber is great influenced when injection/mold nozzle sides are different more than that of the same. Consequently, the mechanical properties of short carbon/glass fiber reinforced polypropylene arc improved as the nozzle sides are the same in injection mold sides.

• Journal of Fashion Business
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• v.10 no.5
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• pp.135-158
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• 2006

The purpose of this study was to provide for the useful fundamental data by developing an appearl sizing system according to body types for Chinese Adult Female. Thus, it was to improve of fittness and coverage rate of exporting domestic clothing to China. For study, It was measured 1360 female women aged between 19 and 50 who resident in Beijing and Shanghai in China. as a sample, 1381 female women was seleted for development of apparel sizing system. Thus, this study was to characterize body types of Chinese adult female by classifying them into groups and set coverage rate of ready-made clothes by developing an apparel sizing system according to the Women's Wear Specifications(GB/T 1335.2-1997), National Standards of People's Republic of China. As for the method of this study was done during Jun. 23 $\sim$ Aug. 7, 2004. Data analysis were processed by SPSS WIN 10.0 Program was used to for technical statistical analysis. The result was as follows: The clothes dimension for upper and lower body and the coverage rate of body size that had the highest appearance ratio from the entire group was Y-type 160-84$\cdot$160-64(4.6%) and the section 160cm 32.4%, A-type 160-88$\cdot$160-72(3.3%) and the section 160cm 28.1%, B-type 155-88$\cdot$155-78(3.8%) and the section 155cm 27.8%, C-type 150-96$\cdot$150-88(2.5%). The result By setting of representative size number and production coverage rate for Chinese adult female. The representative size number of the entire group was set for 150-80A$\cdot$150-64A(1.0%), 155-84A$\cdot$155-68A(2.6%), 160-88A$\cdot$160-72A(3.3%), 165-84A$\cdot$165-68A (2.8%), 170-96A$\cdot$170-80A(0%). The production coverage rate for each representative size number was SS size the section 150cm 2.8%, size the section 155cm 17.0%, M size the section 160cm 31.6%, L size the section 165cm 25.0%, XL size the section 170cm 12.6% that covered 85.0%.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.394-400
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• 2010

This study examined the effects of particle size on characteristics of cement by controlling the particle size of commercial cement. Through a size adjustment, the cement has increasing more of particles that are less than $10{\mu}m$ in size so the initial reaction time has been shortened as a result of improvement in the early hydration reaction. Additionally, it showed a great characteristics of strength from the early age and the initial hydration heat has been increased as well. In the upper and middle parts cements, the initial hydration reaction rate contribution is high with the $10{\mu}m$ compared to original cement. So the initial hydration reaction rate is improved and as a result, it also showed relatively high hydration heat as well. Additionally, adiabatic temperature also showed an increase rate in the results.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.84-91
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• 2020

The efficiency of the synthetic magnesium silicate used in basic polyols and edible oil purification is evaluated by its purification ability and filtration rate and is affected by the particle size and surface area of magnesium silicate. In this study, it was investigated the change on the particle size of magnesium silicate was influenced by the reaction temperature, injection rate, injection order (Si, Mg) and Mg/Si reaction mole ratio. The synthesized magnesium silicate was compared and analyzed for the synthesis, grinding, and refining processes. In the synthesis process, the reaction temperature and feed rate did not affect the average particle size change of magnesium silicate, while the reaction molar ratio of Mg / Si and the order of injection acted as main factors for the change of average particle size. The average particle size of magnesium silicate increased by 8.7 ㎛ from 54.4 ㎛ to 63.1 ㎛ at Mg injection when Mg molar ratio increased from 0.125 to 0.500, and increased by about 4.8 ㎛ from 47.3 ㎛ to 52.1 ㎛ at Si injection. The average particle size according to the order of injection was 59.1 ㎛ for Mg injection and 48.4 ㎛ for Si injection and the difference was shown 10.7 ㎛, therefore the filtration rate was about 2 times faster under the condition of Mg injection. That is, as the particle size increases, the filtration time is shortened and washing filtration rate can be increased to improve the productivity of magnesium silicate. The cake form of separated magnesium silicate after filtration becomes a solid through drying process and is used as powdery adsorbent through the grinding process. As the physical strength of the dried magnesium silicate increased, the average particle size of the powder increased and it was confirmed that this strength was affected by the reaction molar ratio. As the reaction molar ratio of Mg / Si increased, the physical strength of magnesium silicate decreased and the average particle size after grinding decreased by about 40% compared to the average particle size after synthesis. This reduction of strength resulted in an improvement of the refining ability due to the decrease of the average particle size and the increase of the amount of fine particle after the pulverization, but it resulted in the decrease of the purification filtration rate. While the molar ratio of Mg/Si was increased from 0.125 to 0.5 at Mg injection, the refining ability increased about 1.3 times, but the purification filtration rate decreased about 1.5 times. Therefore, in order to improve the productivity of magnesium silicate, the reaction molar ratio of Mg / Si should be increased, but in order to increase the purification filtration rate of the polyol, the reaction molar ratio should be decreased. In the synthesis parameters of magnesium silicate, the order of injection and the reaction molar ratio of Mg / Si are important factors affecting the changes in average particle size after synthesis and the changes of particle size after grinding due to the changes of compressive strength, therefore the synthetic parameter is an important thing that determines productivity and refining capacity.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.514-521
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• 2016

The High Efficiency Video Coding (HEVC) standard provides superior coding efficiency by utilizing highly flexible block structure and more diverse coding modes. However, rate-distortion optimization (RDO) process for the decision of optimal block size and prediction mode requires excessive computational complexity. To alleviate the computation load, this paper proposes a new moment-based fast CU size decision algorithm for intra coding in HEVC. In the proposed method, moment values are computed in each CU block to estimate the texture complexity of the block from which the decision on an additional CU splitting procedure is performed. Unlike conventional methods which are mostly variance-based approaches, the proposed method incorporates the third-order moments of the CU block in the design of the fast CU size decision algorithm, which enables an elaborate classification of CU types and thus improves the RD-performance of the fast algorithm. Experimental results show that the proposed method saves 32% encoding time with 1.1% increase of BD-rate compared to HM-10.0, and 4.2% decrease of BD-rate compared to the conventional variance-based fast algorithm.

• Journal of Preventive Medicine and Public Health
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• v.7 no.1
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• pp.191-196
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• 1974

Recently, during several years the number of ideal children have not changed at all. Because the most of Korean people considered that son is necessary absolutely for dependence in old age inheritance of family line and holding ritural and so on. Threfore, without revolution of value system for children we could no more expect to reduce fertility rate. The survey is intended to compare the characteristics between those women who want two or less number of ideal children and all married women(regardless the number of ideal children). The results showed as follows: The women who want small size of family were younger and little better educated than those of all married women. The age at marriage of women who want small size of family was older than that of all married women. The conducted rate of induced abortion and acceptance rate of contraception among those women who want small size of family were higher than those of all married women. The rate of those who want less than 2 children socalled ideal No. among all married women was 3.9 percent.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.312-318
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• 2008

The objective of this study was to investigate the changes in ice dendrite size during freezing process in gelatin matrix as a model food system in order to provide mathematical relation between freezing condition and ice dendrite size. Gelatin gel as a model matrix was frozen in unidirectional Neumann's type of heat transfer. The thermograms' analysis allowed to determine the freezing temperature of the sample, the position of the freezing front versus time, and thus, freezing front rate. The morphology of ice dendrites was observed by scanning electron microscopy after freeze-drying. We observed that the means size of ice dendrite increased with the distance to the cooling plate; however, it decreased with the cooling rate and the cooling temperature. In addition, the shorter durations of the freeze-drying process was shorter decreeing the decreased the freezing front rate, resulted in their resulting in a larger pore size of the ice dendrite pores for the sublimation channel of that operate as water vapor sublimation channels. From these results, we could derive a linear regression as an empirical mathematical model equation between the ice dendrite size and the inverse of freezing front rate.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.139-141
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• 2007

Compression tests were carried out to investigate morphologies of compressed specimen, deformation microstructure and stress-strain relation in high-nitrogen austenite stainless steel. Tests were performed under a wide range of temperature and, with true strain rates up to $\dot{\varepsilon}$ =0.05, 0.1, 0.5 and $1.0s^{-1}$. The activation energy of loading force was equal to plastic deformation energy within the temperature range of $900^{\circ}C$ to $1250^{\circ}C$. Dynamically recrystallized grain size decreased with an increasing strain rate and temperature. Flow stresses and deformation microstructures, were used to quantify the critical strain rate and recrystallized grain size. The grain size versus strain rate-temperature map obtained in the study was in good agreement with the deformation microstructures of compressed specimens.