• Proceedings of the KSR Conference
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• 2011.05a
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• pp.613-618
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• 2011

More than 7 million persons use Seoul Metropolitan Subways (SMS) everyday and the number has been in increasing trend. With the increasing trend of concerns on indoor air quality(IAQ), the management of IAQ has become an important issue, especially in case of subway operators, because most of subway lines are placed underground with poor ventilation condition. The ultimate object of study develop independent cleaning device that reduce efficient fine particle and $CO_2$. Urban subway has characteristics about proper clean air flow, must be installed in narrow space and maintenance cycle has enough time. Two layered electrically pre-charged filters were used for removing particulate matters and gas absorbers are packed between two layer filters for removing gases pollutants such $CO_2$, VOCs and HCHO. Urban subway has characteristics about proper clean air flow, must be installed in narrow space and maintenance cycle has enough time. SCAP prototype is producted as all in one method which decrease fine dust, $CO_2$ and noxious gas. and basic test carry out with quantity of wind, a gap of pressure, sampling efficiency.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.634-641
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• 2013

Condensing species behaviour downstream of a combustor was discussed with particle size distribution in this study. The effects of operating conditions in a biomass combustion facility, i.e. concentration of condensing species, temperature gradient, residence time and injection of adsorbents, on particle size distribution were investigated. Pyroligneous liquid which was completely vaporized at the temperature higher than $350^{\circ}C$ was used as a representative of condensing gaseous species. We found that particle size downstream of a combustor increased with increasing heating temperature (i.e. concentration of condensing species) and residence time. However, temperature gradient was not an important factor to control the particle size. The addition of $SiO_2$ precursor as an adsorbent could effectively prevent the particle formation by adsorbing condensing gaseous species on $SiO_2$ particles, and increased the particle size up to 300 nm, resulting in increasing particle removal efficiency in a conventional air pollution control device.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1520-1524
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• 2004

This paper describes the development of a robotic maintenance system for use in a maintenance operation of the nozzle dam in a water chamber of a steam generator at the Kori nuclear power plant in Korea. The robotic maintenance system was designed to minimize the personnel exposure to a hazardous radioactive environment. This robotic maintenance system is operated by a teleoperated control which was designed to perform the nozzle dam maintenance tasks in a remote manner without endangering the human workers. Specific maintenance tasks involve the transportation, insertion, and removal of nozzle dams in a water chamber inside a steam generator via a narrow man-way entrance port. The developed robotic maintenance system has two major subsystems: a two degrees of freedom guiding device acting as the main guiding arm and a master-slave manipulator with a kinematic dissimilarity. The mechanical design considerations, control system, and capabilities of the robotic maintenance system are presented. Finally, a graphical representation of the nozzle dam maintenance processes in a simulated work environment are also demonstrated.

• Electrical & Electronic Materials
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• v.9 no.2
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• pp.180-187
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• 1996

The use of preformed copolymers and their cross-linking have been attempted in order to improve the intrinsic fragility of monolayers and Langmuir-Blodgett (LB) films and to make their technological applications. It has shown that an imidization followed a polyion-complexation can stabilize the LB films against heat and solvents. And, when the polymer structure was properly designed, concurrent removal of the alkyl tails together with imide formation could be accomplished. In this paper, the monolayers of the polymers which were polyion-complexed with PAA at the air-water interface can be transferred onto solid substrates such as porous fluorocarbon membranes filter and quartz crystal microbalance. The properties of the monolayers and the LB films will be discussed by .pi.-A isotherms, FT-IR, DSC, deposition ratio, QCM, and SEM. In addition, it was attempted to investigate the response characteristics of polymer LB films to the organic gases by the use of QCM.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.2
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• pp.152-160
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• 2016

The market demand for diesel engine tends to increase in general passenger cars as well as commercial vehicles because of its advantages. However, to meet the vehicle emissions regulation which will be more stringent in the future, it is necessary to plurally apply all after-treatment technologies such as diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), lean NOx trap (LNT) and selective catalytic reduction (SCR), and so on. Accordingly, the exhaust after-treatment system for diesel vehicle requires the technology of minimizing the numbers of catalysts by integrating every individual catalysts. The purposes of this study is to develop hybrid exhaust after-treatment device system which simultaneously uses LNT/DPF and SCR/DPF catalyst concurrently reducing NOx and particulate matter (PM). As the results, the hybrid system with $NH_3$ generated at LNT/DPF working as a reducing agent of SCR/DPF catalyst, improving NOx conversion rate, was found to be more excellent in de-NOx performance than that in LNT/DPF alone system.

• Journal of Chest Surgery
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• v.13 no.2
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• pp.134-137
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• 1980

This represents a case report of the retained polyethylene catheter fragment in superior vena cava. A 39 year old male was admitted to this Korea University Hospital a short time after compression wound on abdomen with heavy cement material in emergency room, a polyethylene catheter was introduced into the right subclavian vein through a needle. But when the polyethylene catheter was attempted to withdraw the catheter was severed by the beveled tip of the needle. Later that day, chest X-ray disclosed the presence of the fragment extending from right subclavian vein to the superior vena cava. {Fig. 1 and Fig. 2]. Local exploration by way of an infraclavicular incision was unsuccessful in locating the catheter fragment. Another attempt was then made remove the catheter by means a biotome, which is originally a device for the biopsy of the myocardium, introduced through the right great saphenous vein. This procedure, though well tolerated by the patient, was in vain. After 11 days later, during that time he was taken a laparotomy with drain, another operation for removal of retained catheter fragment was performed through median sternotomy. After exposure of the right subclavian vein, innominate vein, and superior vena cava, an incision 1 cm in |length was made directly over the palpated catheter. The catheter immediately was picked upward and removed. The length of the catheter was approximately 8 cm. [Fig 3 ] There was no evidence of thromboembolism from the catheter or other complications. The patient made an uneventful recovery, and was discharged asymptomatic on the 9th postoperative day.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.27-31
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• 2010

It is a well known fact that the LCD and Semiconductor Devices are a central part of IT industry which is important in the present and the future. But the biggest problem of Semiconductor and LCD manufacturing is maintaining a cleaning room environment. For this reason, the soft X-ray type Ionizer was used as the electrostatic reducer device, which protects damage of the product against electrostatic discharge in the manufacturing process. Therefore it is a essential important factor during Semiconductor and LCD production process. But the soft X-ray has a intrinsic problem with harmful to human being in case of soft X-ray exposure. That's reason we have the research to solve above problem and made an apparatus that it was covered with shielding structure to protect X-ray radiation to outside. And besides, it has a possibility to eliminate the charged electrostatic in the narrow space through the slot for Ion emissions with dual soft X-ray sources on the both side. It is also not make the particles from itself when it has been operated.

• The Journal of the Korean dental association
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• v.54 no.7
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• pp.501-512
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• 2016

We evaluated a self-inflatable osmotic tissue expander for its utility in creating sufficient soft tissue elongation for primary closure after bone grafting. Six patients with alveolar defects who required vertical augmentation of >6 mm before implant placement were enrolled. All had more than three prior surgeries, and flap advancement for primary coverage was restricted by severely fibrosed scars. Expanders were inserted beneath the flap and fixed with a screw. After 4 weeks, expander removal and bone grafting were performed simultaneously. A vertical block autograft and guided bone regeneration and distraction osteogenesis were performed. Expansion was sufficient to cover the grafted area without additional periosteal incision. Complications included mucosal perforation and displacement of the expander. All augmentation procedures healed uneventfully and the osseous implants were successfully placed. The tissue expander may facilitate primary closure by increasing soft tissue volume. In our experience, this device is effective, rapid, and minimally invasive, especially in fibrous scar tissue.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.731-734
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• 2004

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric(IMD) layer with free-defect. Polishing pads play a key role in CMP, which has been recognized as a critical step to improve the topography of wafers for semiconductor fabrication. It is investigated the performance of $SiO_2-CMP$ process using commercial silica slurry as a pad conditioning temperature increased after CMP process. This study also showed the change of SEM images in the pore geometry on the CMP pad surface after use with a different pad conditioning temperature.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.4
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• pp.387-394
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• 2013

As the feature size of integrated circuits continues to decrease, the challenge of achieving an oxidation-free exposed layer after photoresist (PR) stripping is becoming a critical issue for semiconductor device fabrication. In this article, the hydrogen plasma characteristics in direct plasma and the PR stripping rate in remote plasma were studied using a $120{\Phi}$ cylindrical inductively coupled plasma source. E mode, H mode and E-H mode transitions were observed, which were defined by matching the $V_{rms}$ and total impedance. In addition, the dependence of the E-H mode transition on pressure was examined and the corresponding plasma instability regions were identified. The plasma density and electron temperature increased gradually under the same process conditions. In contrast, the PR stripping rate decreased with increasing proportion of $H_2$ gas in mixed $H_2/N_2$ plasma. The decrease in concentration of reactive radicals for the removal of PR with increasing $H_2$ gas flow rate suggests that NH radicals have a dominant effect as the main volatile product.