• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.1
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• pp.63-70
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• 2009

The air sterilization systems are investigated experimentally in this paper. The goal is to reduce bacteria, mold and viruses in office air by using a UV sterilizer installed inside a partition panel and wall-mounted unit. These systems allow occupants to turn the system on/off and to control the incoming air speed and direction. The partition air sterilization system conditions and sterilizes the air, and then delivers the clean air into the personal task area through the partition panels, which are connected to the pressurized under-floor plenum. Room air exits through the return grills mounted on the ceiling. The wall-mounted air sterilization system sterilizes the air, and then delivers the clean air to the personal task area from the wall. In this study a full-size experimental environment is established to investigate the immunization performance of these air sterilization systems. A typical office space scale is used in this study in order to find an optimal system to achieve a sterilized healthy micro-environment. Multiple system parameters, including volume flow rate and velocity of supplied air, were regulated during the experiments. The more air contact these air sterilization systems had, the better disinfection performance. Over 90% of eradication ratios were obtained by these two air sterilization systems. The results indicate that these systems can efficiently disinfect office air contamination.

• Clean Technology
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• v.18 no.1
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• pp.14-21
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• 2012

The pros and cons of green building thermal insulation materials and systems have been reviewed from traditional thermal insulation materials such as mineral wool and polyurethane to new thermal insulation materials like VIP and aerogel and future insulating VIM and DIM. VIPs and aerogels with very low thermal conductivity can use for green buildings to significantly increase residential area by reducing energy consumption. Aerogels can be produced as not only opaque and but also translucent forms, thus enabling a wide range of possible building application. For building applications, there are many properties to consider like building site adaptability and mechanical strength, fire protection, cost and environmental impact.

• Clean Technology
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• v.18 no.1
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• pp.69-75
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• 2012

In this study, we executed an environmental impact assessment about recycling of ITO (Indium Tin Oxide), used for touch panel. ITO is mainly used to make transparent conductive coatings for touch and flat screen LCD (Liquid Crystal Display), ELD (Emitting Light Device), PDP (Plasma Display Panel). This demand is increasing little by little. but form current status, ITO is discarded than recycling. It is important to recycling ITO for national strategies about resource conservation, and reduce environmental burden. Also Landfill or incineration of ITO cloud be harmful to the human health in the long-term. Material Life Cycle Assessment method (MLCA) was conducted for comparison landfill and recycling of ITO. MLCA would provide more information for environmental issues and potential environmental impacts of ITO. The study includes two scenarios, the basic scenario is recycling of ITO (10, 20, 30%) and the other scenario is landfill of ITO. In addition, amount of carbon dioxide and energy were calculated.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.263-263
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• 2011

본 연구에서는 DBD (Dielectric Barrier Discharge)방식의 상압 플라즈마를 이용하여 FPD (flat panel display) 공정에 사용되는 a-Si, Si3N4의 식각 공정 특성을 평가하였다. 사용된 DBD 반응기는 기존의 blank planar plate 형태의 Power가 인가되는 anode 부분과 Dielectric Barrier 사이 공간을 액상의 도전체로 채워 넣은 형태의 전극이 사용 하였으며, 인가 Power는 40kHz AC 최대인가 전압 15 kVp를 사용 하였다. 방전 가스는 N2, 반응가스로는 CDA (Clean Dry Air)와 NF3, 액상의 Etchant를 사용 하였으며 모든 공정은 In-line type으로 시편을 처리 하였다. NF3의 경우 30 mm/sec 이송속도 1회 처리 기준 a-Si 1300${\AA}$, Si3N4 1900${\AA}$의 식각 두께를 보였으며 a-Si : Si3N4 선택비는 N2, CDA의 조절을 통하여 최대 1:2에서 4:1 정도까지 변화가 가능하였다. 균일도는 G2 (370 mm${\times}$470 mm)의 경우 5.8 %의 균일도를 보이고 있다. 이외에도 NF3 공정의 경우 실제 TFT-LCD 공정 중 n+ channel (n+ a-Si:H)식각 공정에 적용하여 5.5 inch LCD panel feasibility를 확인 할 수 있었다. 액상 Etchant (HF수용액, NH4HF2)는 버블러를 사용하여 기화 시켜 플라즈마 소스를 통해 1차적으로 활성화 시키고 기존 DBD 반응기에 공급해 주는 형태로 평가를 진행하였다. 식각 특성은 30mm/sec 이송속도에서 a-Si $25{\AA}$ 정도로 가스 형태의 Etchant에 비해 매우 낮은 수준이나 Etching rate 향상을 위한 factor 파악 및 개선을 위한 연구를 진행 하였다.

• Advances in environmental research
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• v.1 no.2
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• pp.125-142
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• 2012

Clean development mechanism (CDM) validity study was conducted to suggest better and more adaptable CDM scenario on water treatment plant (WTP). Potential four scenarios for CDM project; improvement of intake pumping efficiency, hydro power plant construction, solar panel construction and system optimization of mechanical mixing process were evaluated on S-WTP in Korea. Net present value (NPV) of each scenario was estimated based on sensitivity analysis with the variable factors to investigate the CDM validity percentile. Hydro power plant construction was the best option for CDM business with 97.76% validity and $1,127,069 mean profit by 9,813 $tonsCO_2e$/yr reduction. CDM validity on improvement of intake pumping efficiency was 90.2% with $124,305 mean profit by huge amount of $CO_2$ mitigation (10,347 $tonsCO_2e$/yr). System optimization of mechanical mixing process reduced 15% of energy consumption (3,184 $tonsCO_2e$/yr) and its CDM validity and mean profit was 77.25% and $23,942, respectively. Solar panel construction could make the effect of 14,094 $tonsCO_2$ mitigation annually and its CDM validity and mean profit was 64.68% and $228,487, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.6-11
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• 2009

Flow field in a roller conveyor system, induced from the movement of a cassette in which glasses for flat panel display are loaded, is numerically studied in this paper. Contamination on the glass surface by dust particles produced from mechanical friction between roller and cassette is predicted from the analysis results of flow fields. Results show that a large swirl flow is formed under the moving cassette with constant speed. This swirl flow is confined only under the cassette because two main streams from the backward and the fan filter unit on the top ceiling are sufficiently strong. Therefore, it can be said that possibility of the contamination by the particles originated from the friction is relatively low. It is also revealed that flow direction between glass plates is changed according to the speed of the cassette movement due to the shear force of glass plates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.464-469
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• 2019

A remote monitoring panel and control system was developed to control various valves and access control chambers, including gas shutoff valves used in CBR(Chemical, Biological and Radiological) facilities. The remote monitoring panel consisted of a main panel installed in the NBC (Nuclear, Biological and Chemical) control room and auxiliary panel installed in the clean room, and the size was divided into pure control and control including CCTV. This system can be monitored and controlled remotely according to the situation where an explosion door and gas barrier door can occur during war and during normal times. This system is divided into normal mode and war mode. In particular, it periodically senses the operation status of various valves, sensors, and filters in the CBR facilities to determine if each apparatus and equipment is in normal operation, and remotely alerts situation workers when repair or replacement is necessary. Damage due to the abnormal operation of each device in the situation can be prevented. This enables control of the blower, supply and exhaust damper, emergency generator, and coolant pump according to the state of shutoff valve and positive pressure valve in the occurrence of NBC, and prevents damage caused by abrupt inflow of conventional weapons and nuclear explosions.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.207-212
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• 1993

When constructing highly precise production plants, for example, super LSI plants or semiconductor plants, it is important to take the necessary control countermeasures into consideration to obtain the working microvibration environment, which is directly related to product precision. Working environment of a clean room means vibration-free and there are only ultra-miro vibration which human cannot sense. In order to provide an place having a vibration-free working environment with only ultra-micro vibration it is necessary to posses a great number of vibration isolation technlogies, wide-ranging and abundant survey and teat data, and a high level of knowledge enabling comprehensive judgments to be made. In this study, experimental modal analysis is used to analyze the dynamic characteristics of double floor for vibration-proofing near apparatus which generate vibration. It is concluded that the double floor system with rubber pad inserted between floor panel and pedestal is good for vibration proof.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.307-313
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• 2008

In this paper, we propose a novel defects inspection algorithm for TFT-LCD panels. We first compensate the distorted image caused by the camera distortion and the uneven illumination environment using the least squares method and the bezier surface. We find a starting point of each pattern for restricting each pattern. A clean image is compared to each pattern to find defects using modified PCSR-G algorithm. The simulation example shows that our algorithm not only inspects the defects well, but also is robust to the 1-pixel error.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.98-104
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• 2005

A glass transfer robot is used for handling LCDs in the production line of flat panel displays under clean environments. During glass transfer operations of the robot, chattering phenomenon occurs at the robot hand. This deteriorates the accuracy and repeatability of the end-effector of the robot. In this paper, we present the kinematic solution of the robot and then analyze the cause of this chattering phenomenon in view of the mechanism and servo control and propose a practical solution that can reduce the chattering significantly at the robot hand of the glass transfer robot.