• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.117-135
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• 2016

Performance enhancement is one of the most important issues in high performance distributed computing systems. In such computing systems, online users submit their jobs anytime and anywhere to a set of dynamic resources. Jobs arrival and processes execution times are stochastic. The performance of a distributed computing system can be improved by using an effective load balancing strategy to redistribute the user tasks among computing resources for efficient utilization. This paper presents a multi-class load balancing strategy that balances different classes of user tasks on multiple heterogeneous computing nodes to minimize the per-class mean response time. For a wide range of system parameters, the performance of the proposed multi-class load balancing strategy is compared with that of the random distribution load balancing, and uniform distribution load balancing strategies using simulation. The results show that, the proposed strategy outperforms the other two studied strategies in terms of average task response time, and average computing nodes utilization.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.291-294
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• 2003

The Water resources utilization pattern of Jangsung reservoir was studied. The observed precipitation and existing reservoir operation data such as irrigation amount, reservoir storage, river maintenance requirement, flood control discharge were collected for ten years period and analyzed. Major findings of this study are as follows: The observed average, minimum, maximum annual precipitation were 905.1mm, 1,977.3mm, 1,554.3mm during study period, respectively. The average annual irrigation amount was 554.5mm, irrigation amount of drought years of '92 and '94 was 604.6mm, 679.2mm, respectively. However, irrigation amount of extended drought year '95 was 384.9mm. It showed that supplying capacity of Jangsung reservoir was limited when consecutive 2 year drought occurred. The main water resources usage of Jangsung reservoir was irrigation, but flood control discharge exceed irrigation amount exceptionally when high precipitation occurred. The reservoir operation record revealed that discharge for river maintenance was delivered even drought years.

• Journal of the Korean Ceramic Society
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• v.11 no.1
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• pp.19-22
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• 1974

The andalusite that can be found in mica shist near YunChun deposits were studied by means of an optical microscope, X-ray diffraction, thermal analysis of DTA and TGA, chemical analysis and refractoriness test to find out an appropriate method of concentration and purification for the utilization as a raw material of high alumina refractories, with the results: 1. The andalusite are has chiefly contained andalusite, muscovite and biotitei in addition to small amounts of chlorite, kyanite, disapore, quartz, alumandite adn pyrite, which vary from sample to sample. 2. Most of andalusite have occurred as light-red colored columns which are estimated to be an average of 4 by 0.5m/m in length. 3. Samples of andalusite which were dressed by cobbing and hand picking in the deposits have contained an average of 42% andalusite.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.404-413
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• 1998

This study was conducted in order to clarify the factors affecting the number of utilization to health center for the shipyard workers who have been work in exposed environment to solvent. At first the tendencies of the number of utilization to health conte. in accordance with cumulative exposure(CE), lifetime weighted average exposure(LWAE), one's place of duty, work contents, states of using safety apparatus, the degree of the knowledge on handling solvents, exposure year. 1). The increase in the cumulative exposure(CE) war significantly higher in the number of utilization to health center. The group with longer exposure year showed significantly higher number of utilization to health center(p<0.01). Considering the work contents such as power blasting, spray, mixing and touch-up, the group of touch-up showed higher number of utilization to health center and this difference was statistically significant(p<0.001). Those who were not using the safety apparatus, showed higher number of utilization to health center, which was statistically significant(p<0.05). The degree of the knowledge on handling the solvent had no relation with using health center. 2) The results conducted from this study by multiple regression analysis in clarifying the factors affecting the number of utilization to health center, CE, exposure year and using safety apparatus was significant factor in utilization of health center.

• Environmental Engineering Research
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• v.18 no.2
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• pp.85-90
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• 2013

This study is an attempt to quantify rainwater utilization and miscellaneous water demand in Tokyo's 23 special wards, the core of the urban area in Tokyo, Japan, in order to elucidate the potential of further rainwater utilization. The rainwater utilization for miscellaneous appropriate water demands, including toilet flushing, air conditioning, and garden irrigation, were calculated for six different types of building: residential house, office, department store, supermarket, restaurant, and accommodation. Miscellaneous water demands in these different types of building were expressed in terms of equivalent rainfall of 767, 1,133, 3,318, 1,887, 16,574, and 2,227 (mm/yr), respectively, compared with 1,528 mm of Tokyo's average annual precipitation. Building types, numbers and its height were considered in this study area using geographic information system data to quantify miscellaneous water demands and the amount of rainwater utilization in each ward. Area precipitation-demand ratio was used to measure rainwater utilization potential for miscellaneous water demands. Office and commercial areas, such as Chiyoda ward, showed rainwater utilization potentials of <0.3, which was relatively low compared to those wards where many residential houses are located. This is attributed to the relatively high miscellaneous water demand. In light of rainwater utilization based on building level, the introduction of rainwater storage mechanisms with a storage depth of 50 mm for six different types of buildings was considered, and calculated as rainfall of 573, 679, 819, 766, 930, and 787 (mm), respectively. Total rainwater utilization using such storage facilities in each building from 23 wards resulted in the retention of 102,760,000 $m^3$ of water for use in miscellaneous applications annually, and this volume corresponded to 26.3% of annual miscellaneous water demand.

• Child Health Nursing Research
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• v.14 no.1
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• pp.5-13
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• 2008

Purpose: This study was done to describe utilization status of emergency medical service for children at one university affiliated hospital located in Seoul. Data were obtained from the medical records of patients under 13 years of age who visited the ER from January 1 to December 31, 2006. Method: Medical records missing the time of discharge were excluded in the analysis of waiting time, which resulted in 19,766 cases. Data were analyzed using SPSS WIN 14.0 version. Result: There were slightly more boys (58.4%), average age of the children was 3.97 years of age. More children at the aged 1 to 3 years (51.3%) visited the ER. Fever was the most frequent complaint: 5,180 cases (24.38%). The other complaints were head or facial laceration (10.55%), vomiting (9.63%), abdominal pain (8.06%), cough (7.67%), and painful limb swelling (6.34%). Average waiting time before the first medical examination was 17 minutes, and average ER stay time was 3 hours and 23 minutes. Conclusion: The results suggest the need to assign a nurse specialist for pediatric ER to provide more efficient care for the children. Also, extra staff assignment during the evening shift or extending office hours of local pediatricians should be considered.

• Tunnel and Underground Space
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• v.13 no.4
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• pp.260-269
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• 2003

In order to introduce to engineers the suitable calculation techniques of TBM advance rate (ad.) and ultimately promote to understand the designing process, this study was carried out. We analyzed the 17 bored data of TBM which applied to the roadway and water supply tunnels in Korea. From this analysis, it was able to how that the average utilization is 30.83% md the correlation equation of Ad and TBM´s diameter (D) is Ad(m/month) = 506.05ㆍ $e^{-0.1162}$$\times$D than the correlation coefficient ($R^2$) is 0.76. In the object of the W tunnel of Seoul-Busan highspeed railway, the Ad of TBM 5.0mø was analyzed by the variety of empirical models and upper correlation equation. Average Ad of the empirical models was calculated to be larger than one of the upper equations. But considering only the results of 3.0~5.0mø TBM in the 17 bored data, the average Ad by the models belongs to the similar range of bored data. Therefore, when the reliability and representative of parameters are decreased, a reliability test should be carried out through the comparison a variety of empirical models with the upper correlation equation.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.901-906
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• 1997

Ultrafine silicon dioxide($SiO_2$) powder was prepared from tetraethylorthosilicate(TEOS) by the gas-phase reaction. The effects of reaction temperature, flow rate of gas, TEOS concentration, and preheating temperature of reactants on the particle size were investigated. As the reaction temperature increased, average particle size of the silicone dioxide powder became smaller. Smaller particles were also obtained with decreasing the residence time of reactants in the reaction zone. Larger particles having narrow size distribution were produced with the high concentrations of the reactants. The effect of the preheating temperature was not considerable on the average particle size. The range of average particle size was from 30 nm to 58 nm depending on experimental conditions.

• Journal of The Korean Association of Information Education
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• v.24 no.1
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• pp.39-48
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• 2020

This study analyzes PISA's ICT background survey on OECD countries published in December 2019 to analyze ICT accessibility and utilization of each subject. In Korea, ICT accessibility at home is 40.40%, ranking 17th, slightly higher than the OECD average (43.01%). Access to schools is 40.40%, ranking 21st below the OECD average(43.01%), which has improved from the lowest group to three in the middle three years ago. In nine subjects, the proportion of students using digital device in the classroom is 2.96%, well below the OECD average(8.22%), and ranked 31st in the OECD country. This shows that the state needs a change in education policy in order to cultivate the talent needed for the AI era.

• Resources Recycling
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• v.14 no.6 s.68
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• pp.37-43
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• 2005

[ $LiCoO_{2}$ ] nanoparticles were synthesized from leach liquor of lithium ion battery waste using flame spray pyrolysis. Electrode Materials containing lithium and cobalt could be concentrated with thermal and mechanical treatment. After dissolution of used cathode materials of the lithium battery with nitric acid, the molar ratio of Li/Co in the leach liquor was adjusted at 1.0 by adding a fresh $LiNO_{3}$ solution. The nanoparticles synthesized by the flame spray pyrolysis showed clear crystallinity and were nearly spherical, and their average primary particle diameters ranged from 11 to 35 nm. The average particle diameter increased with an increase in the molar concentration of the precursor. Raising the maximum flame temperature by controlling the gas flow rates also led to an increase in the average diameter of the particles. The $LiCoO_{2}$ powder was proved to have good characteristics as cathode active materials in charge/discharge capacity and cyclic performance.