• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.147-152
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• 2001

This study was carried out to investigate the effect of application time and amount of liquid pig manure on growth and yield of rice plant and infiltration water quality. Liquid manure treatment with higher application rate and closer application time to transplanting time showed higher plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and lodging. In liquid manure treatment with higher application rate, number of panicles per hill and number of spikelets per panicle were higher but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample was increased with increasing application amount of liquid manure and closer application time to transplanting of rice plant. With consideration yield of rice and environment such as groundwater quality, the proper application amount were 150% and 100% of recommending N fertilizer level (11kg) at before winter and April or May treatment, respectively.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.430-435
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• 2008

To maximize the obtained polysaccharides from Phellinus linteus mycelia, effects of extraction and purification conditions including dialysis time (8, 16, 24, 48 h) on an amount of the polysaccharides were investigated. As extraction temperature ($50{\sim}95^{\circ}C$), ratio of solvent volume to the dry weight of mycelia (10, 15, 20, 25 ml/g), extraction time(2, 4, 6, 8 h), final concentration of ethanol (70, 75, 80, 85%), and aging time (1, 4, 8, 16 h) increased, an amount of the polysaccharides was increased. An increase in precipitation time up to 24 h increased an amount of the polysaccharides but a further increase in precipitation time after 24 h did not changed largely an amount of the polysaccharides. Three precipitation solvents (ethanol, methanol, acetone) were tested. An amount of the polysaccharides was increased in order to acetone, ethanol, and methanol. On the optimal extraction condition, extraction temperature, ratio of water volume to the dry weight of mycelia, and extraction time were $95^{\circ}C$, 25 ml/g, and 8 h, respectively.

• Journal of Families and Better Life
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• v.14 no.4
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• pp.145-162
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• 1996

The purpose of this study was to compare time use pattern of Korean working couples with those of Japanese counterparts. The data for240 Korean couples living in Seoul and 162 Japanese couples living in Tokyo were collected using structured questionnaire and time diary. The time use patterns of couples were analyzed according to employed status of wives. The results were as follows. The similar time use patterns were found between couples of two country. However the amount of time allocated for daily activities was found to be somewhat different. The amount of time spent by husbands on paid and house work was found to be different according to their wives employment status. The orean husbands of full-time employed wives and the Japanese husbands of part time employed wives spent the longest time on paid work. The Japanese husbands of full-time employed wives spent much more time on housework than those of Korean counterparts did. The social-cultural time of Korean couples was enerally longer than that of Japanese couples. The Korean couples spent more time on watching TV whereas the Japanese couples used more time doing family activities hobbies and moving for social-cultural activities.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.457-463
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• 2006

Recently proposed control scheme for a stable teleoperation, which was based on two-port time-domain passivity approach[21], has been successful for a contact with high stiffness environments. However, we found several conservatisms during the contact with deformable environments and unconstrained motion. The two-port time-domain passivity controller was excessively dissipating energy even though it was not necessary for some cases of an unconstrained motion and soft contact. The main reason of those conservatisms was on the fact that the two-port time-domain passivity controller was activated without considering the amount of energy dissipation at the master and slave manipulators. Especially, the exclusion of the slave manipulator from the two-port was the dominant reason of the conservatisms. In this paper, we consider the amount of energy dissipation at slave manipulator for designing the time-domain passivity observer and controller. The measured interaction force between slave manipulator and environment allow the time-domain passivity observer to include the amount of energy dissipation at the slave manipulator. Based on the modified passivity observer, reference energy following method[24] is applied to satisfy the passivity condition in real-time. The feasibility of the developed methods is proved with experiments. Improved performance is obtained for an interaction with deformable environments and an unconstrained motion.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.258-263
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• 2005

Statement of problem. Implant screw loosening has been remained a problem in implant prosthodontics. The time needed to insert screw driver into abutment screw head should be shortened for the purpose of decreasing the chair time. Purpose. The purpose of this study was to investigate the effects of the design of abutment screw driver on the amount of time for insertion of screw driver into abutment screw head. Material and methods. Hexagonal and rectangular types of abutment screw drivers were used. The original abutment screw drivers were modified by grinding acute angle of the screw driver tip (modified drivers). Group 1 : hexagonal type abutment screw and original driver Group 2 : hexagonal type abutment screw and modified driver Group 3 : rectangular type abutment screw and original driver Group 4 : rectangular type abutment screw and modified driver UCLA lab analogues were located in acrylic resin block. The angulations of them were 0 and 20 degrees. The times needed for insertion were measured. Group 1 and 3 were used as controls. Results. 1. Group 2 showed shorter insertion time than group 1, regardless of implant angulations (p<.05). 2. Group 4 showed shorter insertion time than group 3, regardless of implant angulations (p<.05). Conclusion. Modified abutment screw drivers required less amount of time to insert screw driver into abutment screw head. Modification of abutment screw driver was beneficial.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.297-304
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• 1989

The dielectric properties of SrTiO3 GBL Capacitor have been investigaetd as a function of the second heat treatment time and the amount of Ta. The grain size of semiconductive SrTiO3 after sintering at 1,46$0^{\circ}C$ for 4 hours in N2/H2 atmosphere increased as the amount of Ta increased, and then decreased as the amount of Ta exceed 0.01 mole. Also, the dielectric constant after the second heat treatment showed the same tendency. When the semiconductive SrTiO2 was second heat treated at 1,10$0^{\circ}C$ in air with varying time, the dielectric constant increased as the second heat treatment time increased up to 60 minutes, and then decreased as the time became longer than 60 minutes.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.22-27
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• 2015

Processing of low toughness graphite material requires high-speed machine tools and DLC coating. In this study, results of investigation of the tool wear and machining properties of the DLC coating according to the thickness, and the machining time of the tool used for the machining of graphite electrodes, were as follows. 1. DLC coating thickness shows a larger wear amount of the tool center in accordance with thickness; the wear amount of the tool increases in proportion to the machining time. 2. The difference between the amount of wear depending on the processing time shows edge portions larger than the tool wear amount in the center. This amount of wear of the tool edge is formed since the rotating torque is in contact with the graphite material surface significantly more than the central portion. 3. The thicker the DLC coating, the more the coating tool eliminated of the coating area by the interface between the cemented carbide tool being coated with an increased friction of the graphite material and the DLC coating area.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.117-124
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• 2021

The development of IOT technology and artificial intelligence technology is promoting the smartization of manufacturing system. In this study, data extracted from acceleration sensor and current sensor were obtained through experiments in the cutting process of SKD11, which is widely used as a material for special mold steel, and the amount of tool wear and product surface roughness were measured. SVR (Support Vector Regression) is applied to predict the roughness of the product surface in real time using the obtained data. SVR, a machine learning technique, is widely used for linear and non-linear prediction using the concept of kernel. In particular, by applying GSVQR (Generalized Support Vector Quantile Regression), overestimation, underestimation, and neutral estimation of product surface roughness are performed and compared. Furthermore, surface roughness is predicted using the linear kernel and the RBF kernel. In terms of accuracy, the results of the RBF kernel are better than those of the linear kernel. Since it is difficult to predict the amount of tool wear in real time, the product surface roughness is predicted with acceleration and current data excluding the amount of tool wear. In terms of accuracy, the results of excluding the amount of tool wear were not significantly different from those including the amount of tool wear.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.433-442
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• 2007

This study was conducted to investigate the quality characteristics of Sulgitteok prepared with different ratios of lotus leaf powder, over for 4 days of storage. As the amount of lotus leaf powder increased, the moisture contents of the lotus leaf Sulgitteok decreased; however, this was not consistent for all samples during storage. As the content of the lotus leaf powder increased, the L-values of the lotus leaf Sulgitteok significantly decreased, and the a- and b-values also significantly increased at day 0. The L- and a-values did not show large differences with storage. The total cell count of the lotus leaf Sulgitteok prepared with the 4% lotus leaf powder (LL4) was considerably lower than the other samples at 2 days of storage, indicating that microorganisms were inhibited by increasing amounts of lotus leaf powder. The hardness, gumminess, and chewiness of the lotus leaf Sulgitteok decreased as the amount of lotus leaf powder increased; however, they increased as storage time passed. Increasing amount of lotus leaf powder and the storage time resulted in greater reductions in adhesiveness. Springiness was not significantly different according to the amount of added lotus leaf powder or the storage time. Increasing storage time caused cohesiveness to decreased in all samples except LL2. Also, the results of the sensory evaluation showed that the LL2 lotus leaf Sulgitteok had the highest scores. In conclusion, the lotus leaf Sulgitteok prepared with the 2% lotus leaf powder (LL2) was superior.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.243-253
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• 1994

Work environments have been changed with the advent of new technologies, such as computer technology. The newer technologies, the more changes in our work conditions. However, human cognitive limits can't keep up with the change of work environments. Mental workload has been an important factors in designing modem work environments such as human-computer interaction. Designing man-machine systems requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under an urgent situation, human operator may suffer the work stress, work error, and resultant deleterious work performance. To describe the work performance in the urgent work situations, with time stress and dynamic event occurence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount system processing time, information density) were evaluated using such dependent variables as reaction time, number of error, and number of failure. The results of statistical anlysiss indicate that the amount of information effected on all of five dependent measure. Number of failure and number of secondary task score were effected by both amount of information and operational speed of system, but reaction time of secondary task were effected by both amount of information and information density.