• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.225-226
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• 2017

Recently, there has been a growing interest in the development of non-sintered binder to reduce CO2 emissions from the cement clinker manufacturing process and a number of studies have been conducted on fly ashes as an industrial by-product. However, in order to utilize fly ashes as a non-sintered binder, it is necessary to solve problems such as safety issues and economical efficiency due to use of an alkali activator. This study evaluates the material properties and compressive strength characteristics of three types of circulating fluidized bed boiler ashes. As a result, it was confirmed that the characteristics of each binder vary depending on the location of the power plant and the types of raw materials. In addition, it has been confirmed that the fluidized bed boiler ash shows a high compressive strength and can be used sufficiently as an non-sintered binder.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.23-30
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• 2009

Slow sand filtration (SSF) was the first engineered/mechanical filtration process used in drinking water treatment. In SSF, untreated water slowly percolate through a bed of porous sand. Biological activity within the sand bed have the strongest influence on removal efficiency of pollutants by slow sand filtration. In this study, the microbial population distributions in slow sand filters operated at the various operation conditions was evaluated. The concentrations of $10^4$ to $10^5$ CFU per g dry wt. were observed. No significant differences were seen between the number of filter-covered materials. The data indicate that the temperature has affect on population distribution. Also, the light exposure was influenced on microorganism in slow sand filtration according to the heterotropic plate counts. The role of microorganism within the sand media requires further study.

• Ocean Systems Engineering
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• v.12 no.4
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• pp.439-459
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• 2022

This paper describes experimental studies of impact pressure generated by breaking regular waves in shallow water on a vertical cylinder. Experimental work was carried out in a shallow water flume using a 1:30 - scale model of a vertical rigid circular hollow cylinder with a diameter 0.2 m. This represents a monopile for shallow water offshore wind turbines, subjected to depth induced breaking regular waves of frequencies of 0.8 Hz. The experimental setup included a 1 in 10 sloping bed followed by horizontal bed with a constant 0.8 m water depth. To determine the breaking characteristics, plunging breaking waves were generated. Free surface elevations were recorded at different locations between the wave paddle to the cylinder. Wave impact pressures on the cylinder at a number of elevations along its height were measured under breaking regular waves. The depth-induced wave breaking characteristics, impact pressures, and wave run-up during impact for various cylinder locations are presented and discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.55-58
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• 2007

To check the feasibility of SMART (Steam Methane Advanced Reforming Technology)system, an experimental investigation was conducted. A fluidized bed reactor of diameter 0.052 m was operated cyclically up to the $10^{th}$ cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone (domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) system. However, the hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased.

• Water for future
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• v.6 no.1
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• pp.19-28
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• 1973

Presented is the results of a model study about scouring around a bridge pier. 24 different types of piers were inestigated for the depth and width of scouring. The grain size of sand used in the experiment ranges from 0.149 to 2, 380mm, The time required to reach the stable bed formation was about 30min, with the range of Froud number from 0.58 to 0.69. It has been found that the scouring is most severe at the frontal side of the pier and decreases with decreasing a contact angle (between the center line of the pier and tangent to the frontal face). For design purposes, it is recomanded that the contact angle at the frontal face is 25 degrees for a triangular type and 40 deyrees for a circular type respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.3
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• pp.285-307
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• 2009

This paper introduces DICE, a Domain-Independent text Classification Engine. DICE is robust, efficient, and domain-independent in terms of software and architecture. Each module of the system is clearly modularized and encapsulated for extensibility. The clear modular architecture allows for simple and continuous verification and facilitates changes in multiple cycles, even after its major development period is complete. Those who want to make use of DICE can easily implement their ideas on this test bed and optimize it for a particular domain by simply adjusting the configuration file. Unlike other publically available tool kits or development environments targeted at general purpose classification models, DICE specializes in text classification with a number of useful functions specific to it. This paper focuses on the ways to locate the optimal states of a practical text classification framework by using various adaptation methods provided by the system such as feature selection, lemmatization, and classification models.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.103-109
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• 1997

As the quality of raw water deteriorates, a number of additional treatment techniques have been developed and adapted to water treatment for producing a safe and aesthetically satisfactory drinking water. So, BACFB process as pretreatment in water supply is to be effective to remove dissolved organics. This study performed to find out the effects of HRT and hydraulic characteristics on BACFB reactors in water supply. The flow type in reactor was a high dispersion with complete mixing. As superficial velocity was increased, bed expansion was closed to theoretical values. It was considered that below 30 min HRT could operated to ensure the removal of dissolved organics.

• The Korean Journal of Mycology
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• v.31 no.2
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• pp.53-58
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• 2003

Studies were conducted to investigate the changes of teleomorph of Diatrype stigma on bed-log of shiitake (Lentinula edodes) and appearance of secondary harmful fungi from December 1999 to August 2001. The color of stroma was changed from red brown to dark brown after 12 months. The size of ostioles became smaller and the number of ostioles decreased as time passed. Most of the ostioles disappeared after 20 months from toleomorph formation. Perithecia and ascospores were gradually disappeared, and perithecia containing ascospores were observed at 10% of bed-logs tested after 20 months. Concerning the secondary harmful fungi infecting the bedlog of shiitake after teleomorph of D. stigma, Hypoxylon truncatum (Anamorph : Nodulisporium sp.), Schizophyllum commune and Trichoderma spp. were observed on stroma of D. stigma. Penicillium sp. occurred on spore-horn of Libertella sp. (Anamorph of D. stigma). Besides, Hypoxylon howeianum and some species of Myxomycetes were observed. Also, Libertella sp. appeared again at some bed-logs.

• Korean Journal of Plant Resources
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• v.22 no.6
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• pp.528-534
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• 2009

The study of germination and seedling growth characteristics of Neem under different soil and environment conditions was undertaken. The seed germination started 8 days after sowing in commercial bed soil, whereas, delayed germination was observed in sandy-loam (15 days) and sandy (19 days) soil. The highest germination (73.33%) was observed in commercial bed soil in green house, whereas, the lowest germination was observed in sandy soil (16.67%) and sandy-loam soil (8.33%). The seeds in the open field (sandy soil) also showed poor (10%) germination. The mean number of germination seed/day (GD) and seed germination vigor rate (GV) both were highest in the commercial bed soil with 0.733% and 16.67% respectively in the green house, whereas sandy and sandy-loam soil in green house and open field (sandy soil) all showed much lower GD and GV values. The seedling characteristics of nursery revealed that the seedling grown in the growth chamber in commercial bed soil was significantly higher in all the parameters comparing to others grown in green house and open field. The growth was nearly 7 fold in the chamber compared to that of the green house nursery observed in three months old seedlings. Likewise, HPLC analysis revealed that the green house grown seedling contain higher quantity of pigments compare to the chamber grown seedlings. Among the soils used the commercial soil alone or in combination with sandy and sandy-loam soil in the ratio of 2:1:1 respectively with the temperature of $27{\pm}2^{\circ}C$ showed better for Neem nursery preparation.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.173-175
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• 2015

We simulate the particle bed motions with combustion and reduction in steel making rotary kilns. The particle bed motions are simulated by a Lagrangian approach called Discrete Phase Model (DPM). To reduce the number of tracking particles, the Coarse Grain Model (CGM) was applied. The model for particle motions showed good agreements with experimental results. In addition to the particle motion, the combustion and reduction simulation was performed. The combustion and reduction simulation can consider heat, mass and momentum transfer between the gas phase and particle beds.