• Journal of Internet Computing and Services
• /
• v.7 no.6
• /
• pp.105-112
• /
• 2006

This paper be composed to file system by making a new i_node structure which can decrease Write frequency because this's can improved the file system efficiency if reduced Write operation frequency of flash memory in respect of file system, i-node is designed to realize Cleaning policy of data in order to perform Write operation. This paper suggest Cleaning Algorithm for Write operation through a new i_node structure. In addition, this paper have mode the oldest data cleaned and the most recent data maintained longest as a result of experiment that the recent applied program and data tend to be implemented again through the concept of regional and time space which appears automatically when applied program is implemented. Through experiment and realization of the Flash file system, this paper proved the efficiency of NAND-type flash file system which is required in on Embedded system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.4
• /
• pp.327-331
• /
• 2008

An in-line wet etch/cleaning system was established for the research and development in wet etch process as a formation of electrode such as metal or transparent conductive oxide layer. A reverse moving system was equipped in the in-line wet etch/cleaning system for the alternating motion of glass substrate in a wet etch bath of the system. Therefore, it was possible for the glass substrate to be moved back and forth and it was possible to reduce the size of the system by using the reversing moving system. For the effect of the alternating motion of substrate on the etch rate in the in-line wet etch bath, indium tin oxide(ITO) patterns were obtained through wet etch process in the in-line system in which the substrate was moved back and forth. From the CD(critical dimension) skews resulted from the ADI CD and ACI CD of the ITO patterns, it was concluded that the alternating motion of glass substrate are possible to be applied to the mass production of wet etch process.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.197-198
• /
• 2011

Most of buildings' exterior walls are curtain wall systems and in the respect, the cleaning robot system is the main research item for cleaning and maintenance of them. We have structurely analysed the cases to review on the structural stability of the mullion members where the cleaning robot is attached. The result is showing that the largest stress is formed by the basic wind speed, which is specified in Korean Building Code-Structural.

• KEPCO Journal on Electric Power and Energy
• /
• v.7 no.1
• /
• pp.73-77
• /
• 2021

As the big data analysis technologies has been developed worldwide, the importance of asset management for electric power facilities based data analysis is increasing. It is essential to secure quality of data that will determine the performance of the RISK evaluation algorithm for asset management. To improve reliability of asset management, asset data must be preprocessed. In particular, the process of cleaning dirty data is required, and it is also urgent to develop an algorithm to reduce time and improve accuracy for data treatment. In this paper, the result of the development of an automatic cleaning algorithm specialized in overhead transmission asset data is presented. A data cleaning algorithm was developed to enable data clean by analyzing quality and overall pattern of raw data.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.25 no.4
• /
• pp.542-553
• /
• 2015

Objectives: Many types of dust collector are used for industrial ventilation, with the most common types being the cylinder bag filter system, rectangular bag filter system and cylinder type cartridge filter system. The cylinder type cartridge bag filter, which has more filtering area than other types of bag filter, can increase the pulse time and extend the useful life of the filter. This can save operational costs and installation area. Materials: This study used cylinder type cartridge bag filter equipment and tested the impact of vibration level and filter pressure with different pulse jet cleaning conditions. The final, cleaning efficiency was calculated through input dust mass and cleaning dust mass Conclusions: Two optimum cleaning condition groups were found. The first condition group was $3kgf/cm^2$ pulse pressure, 15 cm pulse distance, 0.2 s pulse time with an H-10 type nozzle. The second condition group was $3kgf/cm^2$ pulse pressure, 15 cm pulse distance, 0.3 s pulse time with an H-10 type nozzle.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.4
• /
• pp.391-398
• /
• 2013

Fuel consumption in a vessel can be reduced by a hull cleaning which has been performed by the industrial robot. It is most important to attach safely and travel on the hull surface for a hull cleaning robot. In this study, therefore, we have developed a drive control system of the hull cleaning robot that enables a stable drive. In addition, operator's conveniences were reflected on the drive control system for comfort robot operation. Through a drive control experiments conducted at a hull test-bed, we demonstrated the drive control performance and conveniences of the developed drive control system.

• Journal of Power System Engineering
• /
• v.18 no.1
• /
• pp.38-44
• /
• 2014

The objectives of this study are to measure the ball recovery rate of cleaning apparatus for plate heat exchanger. Ceramic ball is used for plate heat exchanger cleaning. The main components of cleaning apparatus are comprised of ball collector, ball trap, ejector, pump and plate heat exchanger. The ball recovery rate are obtained with change in recovery time and velocity of water. The results show that the ball recovery rate is slightly increased with increase in the recovery time and the velocity of water over 0.4 m/s in the straight flow. In the case of reverse flow, the ball recovery rate more increased than straight flow. The maximum ball recovery rate of the straight flow and reverse flow reach 83.97% and 86.61%, respectively, when the velocity and cleaning time are 0.5 m/s and 15min.

• Journal of the Korean Society of Safety
• /
• v.14 no.1
• /
• pp.86-92
• /
• 1999

This study was carried out to investigate the effect of chemical cleaning of corrosion product on cooling system made of copper as a basic material and using cooling water as pure water. We studied chemical cleaning condition that minimizes the influence on basic material by means of EDTA solution so as to eliminate the slurry in cooling system. In addition, the proper amount of NALCO-39L (Nitrite-Borate-BZT mixture) as a inhibitor was determined in order to protect the copper in cooling system against corrosion after chemical cleaning and the effect of corrosion resistance on the copper surface treated was excelent in comparison with surface untreated. As a result, we found that the main components of sludge in cooling system produced by corrosion of copper were $Cu_2O$, CuO, Cu, and Fe. The optimum condition of chemical cleaning was 400ppm EDTA solution at $60^{\circ}C$. Inhibitor concentration needed to treat the surface of pure copper was 15～20ppm per unit area and corrosion rate of copper treated with 500ppm inhibitor solution for 72 hrs at $60^{\circ}C$ was remarkably decreased as compared with that of pure copper.

• Textile Coloration and Finishing
• /
• v.32 no.3
• /
• pp.158-166
• /
• 2020

Self-cleaning fabric is a fabric having a function of decotamination via photodecomposition of photocatalyst or wash-off of contaminants on the superhydrophobic surface. TiO₂ is the main photocatalyst for this purpose, but it only functions under UV light which is only a little portion of sunlight, compared to visible light. In this regard, this study aims to investigate Fe-doped TiO₂ for improved photodecomposition from visible light sensitization to apply self-cleaning finishing of PET fabrics. Moreover, the Fe-doped TiO₂ treated PET fabric was further treated with hexadecyltrimethoxysilane to provide superhydrophobicity on the PET fabrics. As a result of this dual treatment, the prepared fabric exhibited excellent photodecomposition of methylene blue with 96.96% in 12h under sunlight and superhydrophobicity with water contact angle of 166.5° and roll-off angle of 7°. This suggested that the excellent self-cleaning functions can be privided to PET fabric via Fe-doped TiO₂ and hexadecyltrimethoxysilane treatment.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.36 no.5
• /
• pp.187-194
• /
• 2020

This study presents the energy-saving sequential control algorithm to handle indoor CO₂ and PM2.5 for the improvement of the air quality of school classrooms. To solve indoor air quality (IAQ) problems, air cleaning and ventilation systems are mainly used for school classrooms. Although air cleaning is able to collect PM2.5, it is difficult to remove harmful gas substances. The ventilation system is suitable to tackle CO and CO₂, the volume ventilation, however, is relatively small. In this paper, to remove CO₂ and PM2.5, the pollutant balance equation for improving indoor air quality is reviewed. The sequential control algorithm of the ventilation and air cleaning system with four levels of criteria is introduced for the effective removal of pollutants. The proposed sequential control algorithm confirms that indoor CO₂ and PM2.5 can be properly controlled below the standard value. In addition, the sequential operation of air cleaning and ventilation systems has shown significant improvement in IAQ compared to the independent ventilation system operation. Particularly, such systems are efficient when outdoor PM2.5 is high.