• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.203-206
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• 2000

In this experiment, an attempt to use pellets($BaTiO_3$, $TiO_2$, ${\gamma}-Al_2O_3$, sludge) for $NO_x$ removal was conducted The effect of pellets on NO removal from simulated flue gas was experimentally investigated for packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50ppm balanced by air, and gas flow rate of $5{\ell}/min$. Ceramic pellets were used for surface discharge and the sludge pellets was added on $BaTiO_3$ and $TiO_2$ to increase $NO_x$ removal rate. In the result, $NO_x$ removal rate using $TiO_2$ was better than other pellets. $NO_2$ segnificatly generated by using $BaTiO_3$ pellets and sludge pellets used with $BaTiO_3$ decreased $NO_2$ generation.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.475-479
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• 2021

There are many difficulties in the applications of smart manufacturing technology in the era of the 4th industrial revolution. In this paper, a test bed was built to aim for acquiring smart manufacturing technology, and the test bed was designed to acquire basic technologies necessary for PLC (Programmable Logic Controller), HMI, Internet of Things (IoT), artificial intelligence (AI) and big data. By building a vehicle maintenance lift that can be easily accessed by the general public, PLC control technology and HMI drawing technology can be acquired, and by using cloud services, workers can respond to emergencies and alarms regardless of time and space. In addition, by managing and monitoring data for smart manufacturing, it is possible to acquire basic technologies necessary for embedded systems, the Internet of Things, artificial intelligence, and big data. It is expected that the improvement of smart manufacturing technology capability according to the results of this study will contribute to the effect of creating added value according to the applications of smart manufacturing technology in the future.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.529-536
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• 2016

The existing methods to estimate the maximum scour depth in the bend of steep gravel bed channel have been evaluated by the hydraulic movable-bed experiments. In the $90^{\circ}$ bend steep-slope channel paved with the fluvial gravels which are uniform in size and have a mean diameter of 43mm, the maximum scour depths due to the flow discharge and the gradient of bed slope have been investigated and compared with the scour depth computed from the equations. The local scour has occurred in conditions that the bed slope is steeper than 0.02 and the $F_r$ is greater than 0.95. Except Lacey's equation and Zeller's equation, the existing methods computing the maximum scour depth overestimate the maximum scour depth in the steep channel with the very coarse gravel bed. However, Lacey's equation with the bed material size and Zeller's equation considering the approach channel gradient and the bend angle may be relatively used to estimate the scour depth in bend of the steep gravel-bed river.

• Analytical Science and Technology
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• v.13 no.1
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• pp.5-11
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• 2000

During the commissioning period in Tonghae thermal power plant which is the largest circulating fluidized bed boiler in the nation, a considerable amount of clinker was formed at FBAC and seal pot. Various attempts, for example, concentration analysis, surface phenomena, thermal characterization, and crystal structure of ash, bed sand, limestone, clinker, and mixture of each gradients have been studied to identify the causes of clinker formed in circulating fluidized bed boiler. As the results, the characterization of black particles in which separated from the clinker is more similar to that of bed sand, on the other hand, white particles are more similar to ash. In addition, the sintering temperature of sand is over $1,200^{\circ}C$ and this temperature was decreased as limestone is added to bed material. The cause of clinker was proved that ash was sticked to molten or sintered sand or limestone in the area of high temperature in the circulating system.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.788-794
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• 2010

Purpose: The fingertip is the most commonly injured part of the hand and its injury frequently results in avulsion or crushing of a segment of the nail bed and fracture of the distal phalangeal bone. Restoration of a flat and smooth nail bed is essential for regrowth of a normal nail, which is important not only for cosmetic reasons but also for tactile capability of the fingertip. It is also anatomical reduction of the distal phalanx to promote patient's cosmetics and prevent nail bed deformity. Absence or no replacement of the nail plate results in obliterated proximal skin fold. When the avulsed nail plate cannot be returned to its anatomic position or when it is absent, we use a synthetic material for splinting the nail bed and alternative reductional method for distal phalangeal bone fracture, especially, instead of hardwares. Methods: From January of 2006 to June of 2009, a total of ten patients and fourteen fingers with crushing or avulsion injuries of the fingertip underwent using the artificial nails for finger splint. We shaped artificial nails into the appropriate sizes for use as fingernail plates. We placed them under the proximal skin fold and sutured to the fold proximally and to the lateral and medial edges of the nail bed or to the distal fingertip. Our splints were as hard as K-wire and other fixation methods and more similar to anatomic nail plates. Artificial nails were kept in place for at least 3 weeks. Results: No artificial nail related complication was noted in any of the ten cases. No other nail fold or nail bed complications were observed, except for minor distal nail deformity because of trauma. Conclusion: In conclusion, in order to secure the nail bed after injury and reduce the distal phalangeal bone fracture, preparing a nail bed splint from a artificial commercial nail is a cheap and effective method, especially, for crushed or avulsion injuries of the fingertip.

• Water Engineering Research
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• v.1 no.2
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• pp.159-168
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• 2000

In this paper, the increment of the local scour depth at piers by constructing the bridge between existing bridges is examined through the experiments in which 5 piers in the non-cohesive bed material in the experimental flume were installed. In the experiments the maximum distance of 25 times of the pier length and the maximum distortion width of 8 times of the pier width were utilized. Through the experimental studies, it was indicated that low flow, which can be characterized as the flow having low Froude numbers, the maximum bed configuration change is obtained when the piers are installed in the straight line in the flor direction without any distortion. However, In the high flow, which can be characterized as the flow having high Froude numbers, the maximum bed configuration change is obtained when the piers are installed with some distortion from the flow direction. The influence of the bed configuration by interaction between bridge piers is changed depending upon the Froude numbers, the distance between piers, and the distortion width between adjacent bridge piers. Also, because the scour patterns are affected by the bed configuration, the maximum scour should be increased by about 60% compared to that in a single pier if the interaction between bridge piers exists. It can be suggested that the maximum scour depth at bridge piers predicted by applying the existing equations should be increased if the interaction between bridge piers exist. Those cases are found when new bridges are constructed successively in the river in the urban area.

• Journal of the Korean Ceramic Society
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• v.55 no.2
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• pp.160-165
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• 2018

This paper investigates the reaction rate of $CO_2$ storing carbonation hybrid reaction by comparing the behavior of carbonation between $Ca(OH)_2$ and fly ash with that of CFBC (Circulating Fluidized Bed Combustion) containing plenty of Free-CaO. Because fly ash with CFBC contains a lot of unreacted CaO, it cannot be used as a raw material for concrete admixtures and its usages are limited. To reuse such material, we stabilized unreacted CaO by carbonation and investigated the carbonation rate. We used a pH meter and a thermometer to check the rate of the carbonization. Also, we set the contents of fly ash with CFBC, $Ca(OH)_2$, flow and fluid of $CO_2$, respectively, to 100 g, 50 g, 100 ~ 1000 cc/min and 400 g based on the content of Free-CaO. We used carbonated water instead of water, and added an alkaline activator to promote the carbonation rate. As a result, the addition of the alkaline activator and carbonated water promoted the rate of carbonation via a hybrid reaction.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.2
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• pp.74-84
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• 1990

The machine tool structures for ultra-precision machining muxt be manufactured with materials which have high static and dynamic stiffness, high damping, a long term dimensional and thermal stability. This study aims at the development of new composite material Epoxy-Granite which exhibits the satisfactory characteristics as a material of ultra-precision mchine tool bed. The Epoxy-Granite testpieces that use epoxy resins as a binder and granite particles as a aggregate have been manufactured so as to examine the material properties about mechanical, thermal and damping characteristics. Experiments were carried out to obtain the proper manufacturing conditions of Expoxy-Granite specimens by varying the several testing conditions such as types of epoxy resins, particle sizes of granite and mixture ratio of epoxy resin and aggregate. Also, when Epoxy-Granite was compared with cast iron, GRANITAN which was imported from CMS of U.K. and granite materials, it has exhibited the superior or almost the same mechanical and damping properties and thermal conductivity, except for the thermal expansion.

• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.225-228
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• 2012

In order to synthesize LED phosphor materials, we have applied three novel synthesis techniques, "melt synthesis", "fluidized bed synthesis" and "vapor-solid hybrid synthesis", in contrast with the conventional solid state reaction technique. These synthesis techniques are also a general and powerful tool for rapid screening and improvements of new phosphor materials.