• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.6
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• pp.1048-1061
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• 1996

The most important practical feature that represents the performance of a washing machine is its ability to remove stains or soils from clothes. There are various tests to measure a washing machine's ability to remove stains or soils from clothes. The results of these tests are dependent upon the kind of soiled fabrics used. Moreover, these results may reflect some aspects of the effectiveness of a washing machine in cleaning clothes due to the paritcular compositions of chemicals which comprise soils in soiled fabrics and the particular conditions in which the results are evaluated. After selecting factors presumed to have a major effect on the cleaning ability of a washing machine and choosing most widely used soiled fabrics, we use experimetal statistics methods to screen real factors from them that influence the cleaning ability of a washing machine in a statistically significant manner for each soiled fabric. Using the least number of experimental rules required to extract the necessary information, we then proceed to present the study on the relations between the sets of selected factors and the soiled fabrics. We would then suggest which soiled fabrics is the best for evaluating the performance in cleaning clothes of a washing machine based on the above study.

• Korean Journal of Occupational Health Nursing
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• v.24 no.3
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• pp.183-193
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• 2015

Purpose: The purpose of this study was to describe cleaning workers' working experiences in Korea. Methods: The data were collected in two focus-group interviews with 9 cleaning workers. The phenomenological analytic method suggested by Colaizzi was used to analyze the data. Results: Five theme clusters and thirteen themes emerged from the analysis. The first theme clusters, 'Dead-end choice' included Limits of elderly women workers, Financial difficulties, Lowered self-esteem. The second theme clusters, 'Facing with discriminatory working environments' included Fear and unfair working conditions. The third theme clusters, 'Potential health problems' included Physical overload, Repeated exposure to hazardous substances and Emotional labor. The fourth theme clusters, 'Excluded from protection of the law' included Gloomy reality and Sexual harassment. The fifth theme clusters, 'Desire to get out of social isolation' included Efforts to maintain the status, Desire to live confidently and Desire to change social recognition. Conclusion: The findings of the study provide understanding on cleaning workers' working experiences to explain by their vision and language and should ensure proper working conditions and environment to live a better life.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.2
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• pp.142-148
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• 2007

The purpose of this study is to suggest the effective ventilation strategies and control methods that can minimize energy cost maintaining acceptable IAQ level in apartment house. The effects of the air-cleaning and heat-recovery ventilation system on IAQ under various operating conditions are investigated based on the experimental and CFD analyzed results. The results can be summarized as follows. (1) When a ventilator is not operated, the concentration of several pollutants may highly show in the house even though environment-friendly building materials are applied. Therefore, a mechanical ventilation system is required to obtain proper ventilation. (2) The pollutant concentration is noticeably deceased under air-cleaning/ventilation mode of air-clinic system, however, pollutant of kitchen is stagnant, because fresh air is not carried into the kitchen. (3) When air-clinic system is only equipped at master bedroom and living room, the system does not effectively deliver fresh air throughout the whole house, and then high pollutant concentration is obtained in each room. In contrast the average pollutant concentration meets the guideline when air-clinic system is installed at each room. (4) The air-cleaning/ventilation mode significantly affects on room ventilation in comparison with ventilation mode only.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.579-585
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• 2003

Recently the utilization of the ozone dissolved de-ionized water(DI-O3 water) in semiconductor wet cleaning process to replace the conventional RCA methods has been studied. In this paper, we propose the water-electrode type ozone generator which has the ozone gas characteristics of the high concentration and high purity to produce the high concentration DI-O3 water for the silicon wafer surface cleaning process. The ozone generator has the dual dielectric tube structure of silent discharge type and the water is both used to electrode and cooling water. We investigate the performance of the proposed ozone generator which has the design goal of the concentration of 7[wt%] and ozone generation quantity of 6[g/hr] at flow rate of 1[$\ell$/min). The experiment results show that the water electrode type ozone generator has the characteristics of 8.48[wt%] of concentration, 8.08[g/hr] of generation quantity and 76.2[g/kWh] of yield and it's possible to use the proposed ozone generator for the DI-O3 water cleaning process of silicon wafer surface.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.295-303
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• 2022

Residential heating systems in South Korea are largely based on the use of ondol pipelines. Heat is transferred to the floor by passing hot water through a metal or plastic pipe buried within the concrete of the floor. Consequently, it is difficult to clean the inside of these pipes after installation. Over time, foreign substances such as scale accumulate in the pipe when the ondol heating method is used for an extended period. Therefore, in the past, pipes were cleaned by removing foreign substances attached to the inside surfaces of the pipes using high-pressure water or by disassembling the pipes and removing foreign substances with chemical agents. Recently, a method for removing foreign substances through the cavitation effect of ultrasound has been proposed. This idea might lead to the development of new technologies for cleaning pipe interiors. Consequently, this study investigated the use of ultrasound to clean pipes embedded in concrete. In this study, devices that generated ultrasonic waves with various frequencies and directions were prepared. After preparing arbitrarily contaminated pipes, the appropriate frequency, output strength, and output direction for each foreign substance were determined through repeated experiments. The results of this experiment could provide important information for future methods of cleaning the interior of ondol piping systems.

• Journal of Conservation Science
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• v.30 no.1
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• pp.95-101
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• 2014

Silver objects tarnish with black from reaction with sulfurous acid or hydrogen sulfide of atmospheric. Blackening of silver objects results from formation of silver sulfide($Ag_2O$) on the surface. Silver sulfide usually is usually removed by conservation treatment. There are several cleaning methods such as chemical, electrochemical and micro-abrasion cleaning, but all of them consume silver. This study investigated the safe and effective parameter of laser cleaning by test on silver coupons. Laser cleaning is a selective process for the removal of specific substances. At first, laser cleaning applied to plain silver coupons, which were not corroded, to find out the safe range of laser energy density. From results, plain silver coupons were not changed at 1064nm below $4.00J/cm^2$ and at 532nm below $2.39J/cm^2$. The corrosion layer(silver sulfide) of artifical corroded silver coupons was removed at 1064nm with $2.39J/cm^2$ by 5~10 pulses and at 532nm with $1.19J/cm^2$ by 5~10 pulses. The removal thickness of corrosion layer was about 13-25nm per a laser pulse using AES analysis. In addition, laser cleaning tested the tarnish silver rings based on the results of silver coupons. As a result of test, the black surface were clean successfully and gave luster of silver, which showed the application possibility of laser cleaning for silver objects.

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.903-913
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• 2014

Objectives: The purpose of the study was to investigate the content analysis of daily tooth cleaning service records by caregivers in a long-term care facility. Methods: The data were analyzed by qualitative research based on content analysis of the daily records of the processes and results of daily tooth cleaning service. Twenty caregivers provided tooth, gum and denture cleaning service after breakfast, lunch, and dinner to 48 elderly residents. The study lasted about two weeks(from August 4 to August 20, 2014). The researcher reconstructed the language by repeatedly reviewing the caregivers statements in the records. The content categories were derived from the records through a reiterative manual comparative analysis. Using constant comparison method, reconstructed meanings were incorporated into various meanings and reanalyzed by final categories called as analytic coding. In order to validate the reliability, 6 times of discussion made the common meanings through a master's degree student and a dental hygiene professor. Results: The caregivers identified lack of understanding and ability to recognize the functional physical and mental changes in the elderly. The elderly had difficulty in recognizing silent communication and daily tooth cleaning. The caregivers were so strenuous in taking care of the daily tooth cleaning service for the elderly. At last, they gave up the daily tooth cleaning service and took on it to the guardians. They found that there was no social supporting network for oral health of the elderly residents. Conclusions: Caregivers had insufficient understanding of the functional physical and mental changes in the elderly residents, and they had difficulty providing daily tooth cleaning service to the elderly due to poor skill and abilities.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.107-115
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• 2013

Purpose: This study was conducted to investigate the change of soft contact lens parameters after eyeliner deposition and compare the cleaning efficiency and the recovery rate of lens parameters by different cleaning methods. Methods: The eyeliner was deposited on three types of soft contact lenses made of different materials for 1 hour, 4 hours and 6 hours and those lenses were washed by the eyeglasses ultrasonic cleaning and by hands. The changes in visible light transmittance, diameter and surface of those lenses were compared before and after cleaning of the lens. Results: The visible light transmittance of soft contact lenses decreased along with the deposition time of eyeliner. The patterns of the eyeliner deposition on soft contact lens appeared differently depending on the physical properties of the lens material. Thus, the largest eyeliner deposition was found on narafilcon A lens. The diameters of hilafilcon B and etafilcon A lenses were decreased, however, the diameter of narafilcon A lens was increased. The cleaning efficiency of the eyeliner deposition was greater with the multipurpose solution by hands than with the eyeglasses ultrasonic cleaner. However, the recovery of lens parameters such as the lens diameter, visible light transmittance and lens surface due to the eyeliner deposition to its original state was limited. Conclusions: From these results, it is suggested to minimize eye makeup when wearing soft contact lens. Furthermore, the reduced wearing time and shorter cycle of lens replacement may be needed by considering a change of lens parameter when the repeat eye makeup is applied.

• Journal of the Semiconductor & Display Technology
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• v.6 no.2 s.19
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• pp.5-10
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• 2007

According to the advantageous features of flash memory, its exploitation and application in mobile and ubiquitous related devices as well as voluminous storage devices is being increased rapidly. The inherent properties that are determined by configuration of flash memory unit might restrict the promising expansion in its utilization. In this paper, we study policies based on threshold values, instead of using global search, in order to satisfy our objective that is to decrease the necessary processing cost or penalty for recycling of flash memory space at the same time minimizing the potential degradation of performance. The proposed cleaning methods create partitions of candidate memory regions, to be reclaimed as free, by utilizing global or dynamic threshold values. The impact of the proposed policies is evaluated through a number of experiments, the composition of the optimal configuration featuring the methods is tested through experiments as well.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1639-1658
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• 2019

Named entity recognition (NER) is an important technique for improving the performance of data mining and big data analytics. In previous studies, NER systems have been employed to identify named-entities using statistical methods based on prior information or linguistic features; however, such methods are limited in that they are unable to recognize unregistered or unlearned objects. In this paper, a method is proposed to extract objects, such as technologies, theories, or person names, by analyzing the collocation relationship between certain words that simultaneously appear around specific words in the abstracts of academic journals. The method is executed as follows. First, the data is preprocessed using data cleaning and sentence detection to separate the text into single sentences. Then, part-of-speech (POS) tagging is applied to the individual sentences. After this, the appearance and collocation information of the other POS tags is analyzed, excluding the entity candidates, such as nouns. Finally, an entity recognition model is created based on analyzing and classifying the information in the sentences.