• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3895-3901
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• 2009

The purpose of this study was to evaluate the effect of professional tooth cleaning and dental health education on dental clearances and dental health behaviors. This study was designed into two groups, 80 persons of control group for dental health education and 80 persons of experimental group for dental health education and professional tooth cleaning. In order to compare education effects, the researcher applied different educational methods. The parameters were the toothbrushing frequency, the average tooth brushing time, the action rate of toothbrushing after lunch, and the rate of using oral hygiene product. The data were analyzed and the following was the conclusion. The frequency of toothbrushing in two groups increased. Toothbrushing frequency of the experimental group was significantly higher than that of preliminary group and control group. The action rate of toothbrushing after lunch in two groups increased. But the experimental group was significantly higher. The score for dental clearances of the experimental group were higher than those of the control group. The data showed statistically significant difference.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.6
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• pp.567-582
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• 2000

We propose a new way of managing flash memory space for flash memory-specific file system based on log-structured file system. Flash memory has attractive features such as non-volatility, and fast I/O speed, but it also suffers from inability to update in place and limited usage cycles. These drawbacks require many changes to conventional storage (file) management techniques. Our focus is on lowering cleaning cost and evenly utilizing flash memory cells while maintaining a balance between the two often-conflicting goals. The proposed cleaning method performs well especially when storage utilization and the degree of locality are high. The cleaning efficiency is enhanced by dynamically separating cold data and non-cold data. The second goal, cycle-leveling is achieved to the degree where the maximum difference between erase cycles is below the error range of the hardware. Simulation results show that the proposed method has significant benefit over naxve methods: maximum of 35% reduction in cleaning cost with even spreading writes across segments.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2013.11a
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• pp.28-29
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• 2013

We have been measuring $CH_4$ flux in a rice paddy in Gimje using the eddy covariance method since July 2011. In order to measure the fast fluctuations of $CH_4$ concentration, an innovative LI-7700 open-path laser spectrometer is used. This high-precision, low power, light weight, low maintenance sensor enables us to operate it on a continuous and long-term basis. One particular feature, among other things, is the self-cleaning lower mirror which decreases maintenance requirements while ensuring more robust, continuous, high-quality dataset. Its cleaning is initiated at user-specified time intervals or a signal strength threshold, and its status is recorded as a diagnostic index. We have noticed that the operation of LI-7700 at Gimje site is quite challenging particularly due to its frequent mirror cleaning requirement and the associated sensitivity of the instrument. In this presentation, we present some field observation data regarding the mirror cleaning and their analysis, thereby suggesting the pertinent operation options for high-quality, maximum data retrieval in the field.

• Journal of Korean Society on Water Environment
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• v.33 no.2
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• pp.123-129
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• 2017

The purpose of this study is to identify potential methodologies to reasonably estimate the effectiveness of road vacuum cleaning in terms of pollution loads reduction. In this context, this study proposes two empirical equations to estimate the amount of diffuse pollution loads removed by road vacuum cleaning. The proposed equations estimate the removed amount of pollution loads respectively taking into consideration of: a) the distance of road vacuum cleaning; and b) the amount of road-deposited sediment(RDS). All of the parameters in these equations were evaluated based on results of field monitoring and laboratory analyses, except for the RDS generation rate. The results of this study suggest that pollutant removal efficiency is 46.3% for $BOD_5$ and 56.4% for TP; discharge ratios for particulate and dissolved $BOD_5$ are 35.0% and 21.2%, respectively; discharge ratios for particulate and dissolved TP are 35.0% and 19.4%, respectively. Average concentrations of pollutants in RDS are $BOD_5$ 977.3 mg/kg and TP 317.6 mg/kg. Some results of a case study imply that both equations can be potentially useful if the adopted parameters are reasonably evaluated. In particular, the RDS generation rate should be evaluated based on monitoring data collected from various road conditions.

• The Journal of Korean Society for School & Community Health Education
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• v.18 no.3
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• pp.55-68
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• 2017

Objectives: Republic of Korea has entered an aged society, recently. As chronic diseases increase, elderly inpatients has been increasing and they have used caregivers for convenience. Accordingly, this study aims to investigate the oral health knowledge and attitude of caregivers on oral health management of elderly inpatients, which would affect the general health and quality of life. Methods: A survey questionnaire was distributed to the caregiver(n=165), at a neurosurgery or orthopedic hospital inpatient ward in Seoul, Gyeonggi-do from April 1 to 14, 2017. We analyzed the data with descriptive statistics analysis, chi-squared analysis and logistic regression analysis by using SPSS 23.0. Results: The response rate to the questionnaire was 92%. Oral health management provided by caregivers to inpatients in the elderly was prevention of oral diseases(92.8%), tooth brushing (89.5%), use of oral care products(68.4%), denture cleaning(90.8%) and oral cleaning(90.8%). Frequency analysis of oral health management in accordance with the educational needs of caregivers was all confirmed statistically significant(p<0.05). In the logistics regression model, oral health knowledge was significantly associated with low oral cleaning(OR=1.58) and oral health attitude was significantly associated with high denture cleaning(OR=1.29) and oral cleaning(OR=1.28) after adjustment for other covariates including gender, age, certification, education level, ward, working years. Conclusions: It is necessary to expand the scope and improve the quality of education that can change the attitudes and behaviors of the caregivers on the oral health management of the elderly on the basis of the current oral health education.

• Particle and aerosol research
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• v.18 no.4
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• pp.129-136
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• 2022

The line width of circuits in semiconductor devices continues to decrease down to a few nanometers. Since nanoparticles attached to the patterned wafer surface may cause malfunction of the devices, it is crucial to remove the contaminant nanoparticles. Physical cleaning that utilizes momentum of liquid for detaching solid nanoparticles has recently been tested in place of the conventional chemical method. Dropwise impaction has been employed to increase the removal efficiency with expectation of more efficient momentum exchange. To date, most of relevant studies have been focused on drop spreading behavior on a horizontal surface in terms of maximum spreading diameters and average spreading velocity of drop. More important is the local liquid velocity at the position of nanoparticle, very near the surface, rather than the vertical average value. In addition, there are very scarce existing studies dealing with microdroplet impaction that may be desirable for minimizing pattern demage of the wafer. In this study, we investigated the local velocity distribution in spreading liquid film under various impaction conditions through the CFD simulation. Combining the numerical results with the particle removal model, we estimated an effective cleaning diameter (ECD), which is a measure of the particle removal capacity of a single drop, and presented the predicted ECD data as a function of droplet's velocity and diameter particularly when the droplets are microns in diameter.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.427-438
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• 2023

Objectives: This study aims to create a safer working environment by examining the working environment of cleanroom cleaning workers through a survey and comparing the differences in perception between workers and managers. Methods: The survey was written based on the working environment and the safety and health management system. In order to improve the quality of the study, we visited the sites in person and conducted an in-depth interview. SPSS Statistics 26 (IBM, USA) was used to analyze the data. Results: Based on the survey, differences were found in chemical used, MSDS sharing methods, risk factors during cleaning work, work environment measurement results, special health examination items, places considered dangerous, and work. Conclusions: It is necessary that there be different work environments and risk factors for cleanroom cleaning workers at respective workplaces. As a result of the survey, there was found to be a difference in perception between workers and managers, and both workers and managers should try to reduce this difference.

• Journal of muscle and joint health
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• v.31 no.1
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• pp.42-52
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• 2024

Purpose: This study aimed to identify the factors affecting compliance with personal protective equipment (PPE) use among medical device reprocessing staff. Methods: This descriptive cross-sectional study included 163 cleaning staff members from ten general hospitals in Seoul and Gyeonggi. Data were collected using self-report questionnaires administered between July and September 2023. Analysis included t-tests, ANOVA, Pearson's correlation coefficient, Bonferroni correction, and multiple regression, conducted using SAS ver.9.4. Results: Statistically significant differences in compliance with PPE were found based on department and exposure to contamination within six months (t=-2.82, p=.007). Attitudes toward PPE (r=.22, p=.006) and awareness of the safety climate (r=.22, p=.006) showed a statistically significant positive correlation with PPE compliance. Factors influencing use of personal protective equipment by cleaning staff during medical device reprocessing were department, compliance with PPE, and awareness of the safety climate. The explanatory power of these factors was 58.0%. Conclusion: Improving PPE compliance and creating a safe cleaning environment entails fostering a supportive safety climate. Additionally, regular training that takes into consideration the characteristics of the cleaning staff, alongside continuous monitoring, is required.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.833-837
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• 2012

This paper proposes a DRAM data retention time enhancement method that minimizes silicon loss and undercut at STI sidewall by reducing the SC1 (Standard Cleaning) time. SC1 time optimization debilitates the parasitic electric field in STI's top corner, which reduces an inverse narrow width effect to result in reduction of channel doping density without increasing the subthreshold leakage of cell Tr. Moreover, it minimizes the electric field in depletion area from cell junction to P-well, increasing yield or data retention time.

• Convergence Security Journal
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• v.23 no.2
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• pp.55-66
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• 2023

Recently, there is an increasing movement to increase the value of AI learning data and to secure high-quality data based on previous research on AI learning data in all areas of society. Therefore, quality management is very important in construction projects to secure high-quality data. In this paper, quality management to secure high-quality data when building AI learning data and improvement plans for each construction process are presented. In particular, more than 80% of the data quality of unstructured data built for AI learning is determined during the construction process. In this paper, we performed quality inspection of image/video data. In addition, we identified inspection procedures and problem elements that occurred in the construction phases of acquisition, data cleaning, labeling, and models, and suggested ways to secure high-quality data by solving them. Through this, it is expected that it will be an alternative to overcome the quality deviation of data for research groups and operators participating in the construction of AI learning data.