• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.29-40
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• 2004

Because cleaning products are part of our everyday lives, it is essential that they should not present significant risks to health. However, many petrochemicals in most soaps and detergents can be absorbed through the scalp and skin and, over time, accumulate in the organs and tissues. This accumulation may result in brain, nerve, and liver damage. Therefore, it is interested in developing non-harmful detergent. According to Korea Research Institute of Chemical Technology, GC-100X may be non-harmful and non-corrosive alkaline ionic water (pH 12). It is composed of hydroxyl radicals and supplemented with xylitol. To evaluate influence of GC-100X on rats and beagles, GC-100X was diluted with distilled water (25%, 50%, and 100% solution respectively). Each of diluted GC-100X was daily treated per oral. In body weight analysis, urinary analysis, ophthalmological test and autopsy, we did not find any significance, but in serum biochemical analysis and hematological analysis, we found some significances in middle dose group compared with control group. These significances in serum biochemical analysis and hematological analysis may be not induced by GC-100X, because it was not found to be significant from control group in histopathological examination. Thus, it is concluded that NOEL(No Observed Effect Level) of GC-100X may be higher than all treatment doses used in this study, and GC-100X may be a non-toxic detergent.

• Asian Journal for Public Opinion Research
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• v.5 no.2
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• pp.63-83
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• 2018

This exploratory research investigated the factors that influence foreign tourists' decision to use dental services in Thailand. The questionnaire was used to collect data from foreign tourists who used dental services in a hospital or dental clinic in Thailand. Data from 233 respondents completed questionnaires were analyzed using frequency distribution, percentages, mean, and standard deviation. The findings revealed that respondents were most likely to be Asian (54.5%) followed by European (33.9%), females (64.8%) aged between 26-35 years (39.1%), business owners (45.9%), and came to Thailand with friends (47.6%). Regarding travel purposes and contact with dental services, most of them travel for pleasure (52.89%) and contact the clinic directly through the Internet(63.95%) The health/medical services used included health check-up (34.48%), dental services (29.22%), and day spa/massage (23.23%). The dental treatment that respondents had completed or planned to do included dental check-up (29.87%), tooth cleaning (26.68%), and tooth whitening (11.41%). Based on the influence of $_7P$ factors towards the respondent's decision to use the dental service, it was found that the average mean score range from 4.33-4.15 which were at the high to the very high level of influence to their decisions. The people factor had the highest average mean score (mean 4.33, SD= 0.604)followed by the price factor (mean 4.32, SD= 0.651), which both had the highest level of influence. The physical evidence factor had the lowest mean score (mean 4.15, SD+0.752) which was at the high level of importance. It should be noted that the factor concerning the modern technology and dental equipment (mean 4.33, SD=0.606) and factor on the quality of service (mean 4.43, SD= 0.598) had the highest mean score followed by the total cost of the trip including services being reasonable (mean 4.37, SD=0.582). Regarding the country factor, it was found that this factor also had highest influence level (mean 4.30, SD=0.67) and affordability had the highest mean score (mean 4.39, SD=0.614).

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.666-670
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• 2013

Recovery method of silicon wafer from defective products generated from manufacturing process of silicon solar cells was studied. The removal effect of the N layer and antireflection coating (ARC) of the waste solar cell were investigated at room temperature ($25^{\circ}C$) by variation of concentration of $H_3PO_4$, $NH_4HF_2$, and concentration and types of chelating agent. Removal efficiency was the best in the conditions; 10 wt% $H_3PO_4$ 2.0 wt% $NH_4HF_2$, 1.5 wt% Hydantoin. Increasing the concentration of $H_3PO_4$, the surface contamination degree was increased and the thickness of the silicon wafe became thicker than the thickness before surface treatment because of re-adsorption on the silicon wafer surface by electrostatic attraction of the fine particles changed to (+). The etching method by mixed solution of $H_3PO_4$-$NH_4HF_2$-chelating agents was expected to be great as an alternative to conventional RCA cleaning methods and as the recycle method of waste solar cells, because all processes are performed at room temperature, the process is simple, and less wastewater, the removal efficiency of the surface of the solar cell was excellent.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.655-663
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• 2017

With the development of ICT technology, the indoor utilization of robots is increasing. Research on transportation, cleaning, guidance robots, etc., that can be used now or increase the scope of future use will be advanced. To facilitate the use of mobile robots in indoor spaces, the problem of self-location recognition is an important research area to be addressed. If an unexpected collision occurs during the motion of a mobile robot, the position of the mobile robot deviates from the initially planned navigation path. In this case, the mobile robot needs a robust controller that enables the mobile robot to accurately navigate toward the goal. This research tries to address the issues related to self-location of the mobile robot. A robust position recognition system was implemented; the system estimates the position of the mobile robot using a combination of encoder information of the mobile robot and the absolute space coordinate transformation information obtained from external video sources such as a large number of CCTVs installed in the room. Furthermore, vector field histogram method of the pass traveling algorithm of the mobile robot system was applied, and the results of the research were confirmed after conducting experiments.

• The Korean Journal of Food And Nutrition
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• v.33 no.2
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• pp.142-148
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• 2020

The purpose of this study was to investigate the prevalence, toxin gene profiles, and enterotoxin producing ability of Bacillus cereus isolated from environment-friendly vegetables and good agricultural practices (GAP) vegetables. A total of 49 vegetables including 40 environment-friendly vegetables and 9 GAP vegetables were tested. The Vitek 2 system was used to identify B. cereus and the PCR was used to detect 6 toxin genes, respectively. B. cereus was detected in 34 (69.3%) of 49 vegetables and the prevalence of B. cereus in GAP vegetables (44.4%) was lower than in the environment-friendly vegetables (75.0%). The detection rates of entFM, nheA, hblC, and cytK enterotoxin genes, respectively, among all isolates were 100%, 97.0%, 88.2%, and 73.5%, respectively. All of the isolates had at least one or more enterotoxin gene and 20 isolates (58.8%) had hemolysin BL enterotoxin producing ability. The risk of food poisoning from the environment-friendly vegetables and the GAP vegetables has been shown as constant. Thus, it is necessary to expand the supply of GAP vegetables showing lower B. cereus contamination than the environment-friendly vegetables. The characteristics of the environment-friendly vegetables and the GAP vegetables that must be consumed after cleaning should be disseminated to consumers regarding food poisoning prevention.

• The Journal of Engineering Geology
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• v.21 no.4
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• pp.369-379
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• 2011

The application of appropriate rehabilitation works can improve productivity and water quality of clogged wells, with extending the operation of the wells for a certain period. This study verified rehabilitation effect of the clogged wells by means of explosive method and air brush surging and by using hydraulic tests, water quality, and geophysical logs (optical and acoustic televiewer logs) before and after the cleaning works on the two wells drilled in bedrock in Mt. Geumjeong, Busan City. Air-brush surging method resulted in maximum 273% increase of the productivity with the concentration of $F^-$, $SiO_2$, and a decrease of turbidity and the concentration of $Cl^-$, $NO_3^-$. The explosive method resulted in maximum 156% increase of the productivity with an increase of the concentration of $F^-$, $SiO_2$ and a decrease of turbidity, $Cl^-$, $NO_3^-$.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.316-322
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• 2006

The current study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of nocotine which has well known as a representative material of environmental tobacco smoke(ETS). Four different preliminary experiments were performed for the evaluation of nicotine removal using photocatalyst-coated construction materials. The photocatalytic removal of nicotine was investigated for five parameters: dry condition of coating tiles, type of coating sol, number of coatings, relative humidity(RH), and input concentrations. Prior to performing the parameter tests, adsorption of nicotine onto the current experimental system was surveyed. All the variables tested in the present study exhibited to influence the photocatalytic decomposition of Nicotine. A dry condition of high temperature and short dry period presented higher photocatalytic oxidation(PCO) efficiency compared to that of low temperature and long dry period. ST-KO3 sol showed higher decomposition efficiency than E-T Sol. The PCO efficiency increased as the number of coating increased. High humidity and low input concentrations exhibited higher PCO efficiency. Consequently, it is noted that the five parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning nicotine in ETS.

• Journal of Convergence for Information Technology
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• v.10 no.8
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• pp.223-228
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• 2020

Objective of this study was to compared the amount of bacteria in the toothbrush according to the management method of the toothbrush in use and the acidity of intraoral bacteria. Toothbrushes in use in more than one month of 50 healthy adults were collected and the number of bacteria and pH of the toothbrushes were measured. When the number of brushings per day was 4, the pH 4.97 and the microbial numbers was the lowest at 42.16(104×CFU/ml). When the replacement period of the toothbrush was 1 month, the pH 5.35 and the microbial numbers was the lowest at 19.80(104×CFU/ml). When stored in the bathroom, the pH 4.78, and the microbial numbers was highest at 149.46(104×CFU/ml). As a result, in order to block the germs of the toothbrush, it is necessary to develop a method that can easily disinfect the contaminated toothbrush at home. In addition, I think that it is necessary to educate about the proper brush cleaning and storage method when teaching brushing.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.428-435
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• 2015

Constructed wetlands (CWs) have been accepted as an attractive and economic alternative to a variety of pollution control and provided potentially valuable wildlife habitat in urban and suburban areas, as well as esthetic value within the local natural environment. CWs are known eco-friendly technology to solve the problem of the climate change and urbanization issues. Numerous studies have been published on the various aspects of a CW. However, there are current limitations about the CW operations such as few design guidelines, poor performance results regarding the simple construction. Therefore, the objective of this research was to suggest an appropriate design and maintenance guidelines for a CW by thorough investigation of site monitoring results. The research also concentrated in redefining and reclassifying CWs, based on literatures made by the Ministry of Environment (MOE) and other organizations. Investigation at 43 CWs in Korea was performed by using collected data and by performing site survey from 2013 to 2014. Based on the results, the best practices among the investigated CWs provided water treatment, wildlife habitat, environmental education, and leisure. Also these CWs conducted a regular maintenance such as vegetation, sediment dredging and cleaning of facilities. Results obtained are intended for use by academics and any organizations involved in CW management.

• Land and Housing Review
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• v.1 no.1
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• pp.35-42
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• 2010

Most of the dredged sand generated from the sewage pipe maintenance project and the government's four-river project are disposed depending on abandonment and filling-up. This is caused by the lack of related recycling technology using dredged sand appropriately and high absorption rate and micro-particles of dredged sand producted from existing sand production system. Thus, this study carried out a quality assessment for the dredged sand produced through the optimum washing and sorting system supplementing problems of existing dredged sand production system as a part of research to examine performance of removing micro-particles and foreign substances. As a result of the assessment, the dredged sand produced through the cleaning and sorting system showed a wide quality improvement effect in absorption rate, 0.08 mm sieve pass amount, clay lump volume and organic impurity content, and it turned out to satisfy both the quality standards of this study, KS F 2573(recycled aggregate for concrete) and KS F 2526(aggregate for concrete) so it could be confirmed that it would be able to be used as an aggregate for concrete in the future.