• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.141-151
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• 1999

To evaluate the effect of cetylpyridinium chloride in a powder form when used concomitantly with a commercial flouride containing tooth paste on inhibition of plaque formation, on gingivitis, and on irritation of oral mucosa, a double--blind, randomized parallel study was set up. Cetylpyridinium chloride was incorporated into a ligh brown colored powder with menthol added for scent. There were no diffemces between the active agent and the placebo which did not contain cetylpyridinium chloride in appearance, color, smell, taste, or dispenser. 98 healthy volunteers were assigned to one of two groups: brushing 3 times a day with flouride toothpaste and cetylpyridinium chloride powder, or brushing 3 times a day with flouride toothpaste and placebo. Before the test period, the subjects received through tooth cleaning and polishing. At basteline, GI, PI, BOP, and GCF of the Ramfjord teeth were measured in the experimental and placebo groups including 58 and 42 subjects repectively, After 4 weeks, GI, PI, BOP, GCF, compliance, irritation of the oral mucosa(redness, pus drainage, edema) and adverse reactions were measured. The PI, GI, and BOP of the experimental group recorded at baseline are 0.19${\pm}$0.19, 0.42${\pm}$0.31, and 0.08${\pm}$0.15. These scores showed significant decrease after 4 weeks of test period(0.11${\pm}$0.15, 0.22${\pm}$0.24, 0.02${\pm}$0.09 repectively at the end of the study) and inhibition of plaque accumulation and resolution of gingival inflammation could be observed. GCF shoed slight increase but this was not statistically different. Comparison of changes in measured scores of control and experimental groupshow GI, PI of the test indices have decreased. Test group showed significantly greater decrease in gingivitis and plaque accumulation after 4 weeks. GCF and BOP also showed greater decrease thant the control group but this difference was not statistically significant. At no time of the study period did any of the subjects show signs of irritation of the oral mucosa or adverse reactions. Following conclusions could be obtained from this study. The combined use of cetl powder and flouride toothpaste showed greater inhibition of plaque accumulation and greater decrease of gingivitis than use of flouride toothpaste with placebo agent.

• Journal of Nutrition and Health
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• v.38 no.3
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• pp.232-241
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• 2005

Today, the role of kindergarten is more important as nutrition provider through snack and meal services. Desirable kinds and amounts of food items at school lunch menu were important factors of nutrients intakes in children. This study was performed to assess the kindergarten's meal service program (snack and lunch) and the consumption amount of lunch according to each dishes. Twenty four institutions that cared over one hundred children were observed at Seoul and Kyunggido area. Well-trained observers checked meal and snack serving activity and foodservice facilities by formal checklist. And using the weighing method assessed the consumption levels of food items at lunch. During 3 days, 30 children in each kindergarten were selected randomly according to age, observers measured serving and residual weight of each food. The data was compiles by performing ANOVA-test using SPSS WIN 10.0. The result were as follows: 1) Foodservice facilities in kindergarten was limited to provide qualified foodservice. $91.7\%$ of institution had kitchen, $41.7\%$ had dinning. The kitchen equipment possession rate was $12.5\%$ (oven), $30.8\%$ (heating cabinet), $58.3\%$ (refrigerator). The rate of using document about foodservice was used $83.3\%$ (menu list), $41.7\%$ (daily foodservice record), $25\%$ (standard recipe). $41.7\%$ of institution employed licensed dietitian. Only $41.7\%$ of subjects preserved meal after daily meal service. 2) Meal serving size was decided by teacher, $54.5\%$ at snack and $43\%$ at lunch and pre-divided individual portion type was $36.4\%$ at snack and $28.6\%$ at lunch. The rate of cleaning activity before meal was $72.2\%$ at snack, $90.5\%$ at lunch. And nutrition or sanitation education activity was more performed at lunch time, for examples brushing teeth activity was $12.5\%$ at snack $85.7\%$ at lunch. 3) The consumption amounts of plain cooked rice was $112.7{\pm}26.1{\cal}g$, cooked rice and cereal was $93.06{\pm}27.97{\cal}g$, curry rice was $208.35{\pm}64.84{\cal}g$ and the consumption amounts of these main dishes was significantly different by age (p < 0.001). The consumption amounts of soup was very different according to children's preference. The consumption amounts of seaweed soup was $120.18{\pm}82.13{\cal}g$, wild sesame and bean-paste soup was $40.64{\pm}23.16{\cal}g$. The consumption range of kimchis was from $6{\cal}g\;to\;13{\cal}g$, jorim (braised food) was from $3{\cal}g\;to\;25{\cal}g$, fried food (include stir fried, deep fat fried, pan fried) was from $14.5{\cal}g\;to\;22{\cal}g$, vegetable dish was from $3{\cal}g\;to\;16{\cal}g$. These consumption amount of each dishes was not reached recommended portion size of nutritionally planning menu by nutritionist.

• Journal of Global Scholars of Marketing Science
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• v.9
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• pp.153-173
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• 2002

The purpose of this study was to investigate the relationships of store service quality, evaluative criteria, perceived risk and impulsive buying behavior of apparels. Data were collected from 481 women living in Busan and analysed by factor analysis, frequency analysis, Cronbach's $\alpha$, multiple regression analysis. The results were as follows: 1. The overall perceived risk was emerged the relationship to the easy-of-care and prestige/brand royalty of apparel products in evaluative criteria. The lower scores of salesperson service and store atmosphere were the high perceived performance risk by consumers. But the color/style of apparel products influenced positively performance risk. The care risk was emerged the relationship to the easy-of-care. And the time convenience loss risk and socio-psychological risk was influenced by prestige/brand royalty of apparel products. 2. The impulsive buying behavior of apparel products was influenced by care risk, performance risk and the store atmosphere. The results showed that perceived risk were influenced partially by store service quality and evaluative criteria of apparel. When were impulsive buying behavior of apparel products, consumers were influenced by care risk that easy-of-care and change after cleaning, and performance risk that coordination and the cost of buying, and then, were influence by store atmosphere and interior.

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.433-447
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• 1999

The objective of this study was to evaluate the effect a chewable tablet containing sodium flouride and lauroyl sodium sulfate on removing plaque and inhibiting gingival inflammation. A randomized parallel study was designed. 100 voluteers participated in the study. There were two test groups each with 30 subject. Test group A was instructed to brush once in the morning, and to use the tablet once in the afternoon and once in the evening. Test group B was instructed to use the tablet three times a day without brushing. There were two control groups each with 20 subjects. Control group A was instructed to brush once in the morning only. Control group B was instructed not to brush all. Two weeks before the test period, the subjects received through tooth cleaning and polishing. At baseline, GI, PI, BOP, and GCF of the Ramfjord teeth were measured in all groups. Bacteria culture was done with the plaque sampled from tooth with the deepest pocket. After 5 days, clinical indices were measured and the bacterial culture was repeated. Control group B was dropped from the study after this period. All the other groups remained and the indices and the culture was repeated after 2 weeks, and 3weeks. Also whether the oral mucosa showed signs of irritation was monitored throughout the test period. Test group A showed less PI, GI, BOP, probing depth, GCF than test group B or control group A. Especially, PI and the BOP was significantly less than that of the group that was instructed to brush once a day. This implies that the added use of this tablet aids in plaque removal in people who brush just once a day. Test group A showed increase of cocci, decrease of motile rods, and decrease of spirochetes after 14-21 days. And this was significantly different from the control group A. At no time of the test period did any of the subjects show signs of irritation of the oral mucosa or adverse reactions. Following conclusions could be obtained from this study. This chewable tablet for enhanced oral hygiene could be used as an adjunct to oral hygiene in people who do not brush adequately. The use of this tablet decreased the number of subgingival bacteria, and this could be effective in plaque removal and for prevention of gingival inflammation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.939-942
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• 2007

Vacuum cleaner is a close life product that can remove various dusts from our surroundings. However well vacuum cleaner clean our environments, many people are looking away from it, due to its loud noise. Its noise causes a big trouble in the usual life, for example, catch calls, TV watching and discussing etc. To reduce these inconveniences, noise reduction methods and systematic design of low noise vacuum cleaner are studied in this paper. At first, sound quality investigation is performed to get the noise level and quality that make people TV watching and catch calls available. Based on the European and domestic customer SQ survey result, sound power, peak noise level and target sound spectrum guideline are studied and introduced. As a second, precise product sound spectrums are designed into each part based on the sound quality result. Fan-motor, brush, mainbody, cyclone spectrums are decided to get the final target sound based on the contribution level. Fan-motor is the major noise source of vacuum cleaner. Specially, its peak sound, RPM peak and BPF Peak, cause the people nervous. To reduce these peak sounds, high rotating impeller and diffuser are focused due to its interaction. A lot of experimental and numerical tests, operation points are investigated and optimization of flow path area between diffusers is performed. As a bagless device, cyclones are one of the major noise sources of vacuum cleaner. To reduce its noise, previous research is used and adopted well. Brush is the most difficult part to reduce noise. Its noise sources are all comes from aero-acoustic phenomena. Numerical analysis helps the understanding of flow structure and pattern, and a lot of experimental test are performed to reduce the noise. Gaps between the carpet and brush are optimized and flow paths are re-designed to lower the noise. Reduction is performed with keeping the cleaning efficiency and handling power together and much reduction of noise is acquired. With all above parts, main-body design is studied. To do a systematic design, configuration design developments technique is introduced from airplane design and evolved with each component design. As a first configuration, fan-motor installation position is investigated and 10 configuration ideas are developed and tested. As a second step, reduced size and compressed configuration candidates are tested and evaluated by a lot of major factor. Noise, power, mass production availability, size, flow path are evaluated together. If noise reduction configuration results in other performance degrade, the noise reduction configuration is ineffective. As a third configuration, cyclones are introduced and the size is reduced one more time and fourth, fifth, sixth, seventh configuration are evolved with size and design image with noise and other performance indexes. Finally we can get a overall much noise level reduction configuration. All above investigations are adopted into vacuum cleaner design and final customer satisfaction tests in Europe are performed. 1st grade sound quality and lowest noise level of bagless vacuum cleaner are achieved.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.903-910
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• 2014

This study examined the treatment characteristics of hard-to-degrade pollutants such as TCE which are found in organic solvent and cleaning wastewater by nZVI that have excellent oxidation and reduction characteristics. In addition, this study tried to find out the degradation characteristics of TCE by Fenton-like process, in which $H_2O_2$ is dosed additionally. In this study, different ratios of nZVI and $H_2O_2$, such as 1.0 mM : 0.5 mM, 1.0 mM : 1.0 mM, and 1.0 mM : 2.0 mM were used. When 1.0 mM of nZVI was dosed with 1.0 mM of $H_2O_2$, the removal efficiency of TOC was the highest and the first order rate constant was also the highest. When 1mM of nZVI was dosed with 0.5 mM of $H_2O_2$, the first order rate constant and removal efficiency were the lowest. The size of first order rate constant and removal efficiency was in the order of nZVI 1.0 mM : $H_2O_2$ 1.0 mM > nZVI 1.0 mM : $H_2O_2$ 2.0 mM > nZVI 1.0 mM : $H_2O_2$ 0.5 mM > $H_2O_2$ 1.0 mM > nZVI 1.0 mM. It is estimated that when 1.0 mM of nZVI is dosed with 1.0 mM of $H_2O_2$, $Fe^{2+}$ ion generated by nZVI and $H_2O_2$ react in the stoichiometric molar ratio of 1:1, thus the first order rate constant and removal efficiency are the highest. And when 1.0 mM of nZVI is dosed with 2.0 mM of $H_2O_2$, excessive $H_2O_2$ work as a scavenger of OH radicals and excessive $H_2O_2$ reduce $Fe^{3+}$ into $Fe^{2+}$. As for the removal efficiency of TOC in TCE by simultaneous dose and sequential dose of nZVI and $H_2O_2$, sequential dose showed higher first order reaction rate and removal efficiency than simultaneous dose. It is estimated that when nZVI is dosed 30 minutes in advance, pre-treatment occurs and nanoscale $Fe^0$ is oxidized to $Fe^{2+}$ and TCE is pre-reduced and becomes easier to degrade. When $H_2O_2$ is dosed at this time, OH radicals are generated and degrade TCE actively.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.174-186
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• 1996

This study was carried out in order to understand the plan, design, constructing and actual condition of management of modernized horticultural facilities in Kyungpook Province which had been constructed from 1992 to 1995 funded by Government support. The aim of this study is to provide reference data for success of the forth project. It was performed by making up a question about driving of project and management condition of equipment after constructing. The results obtained from this study are as follows: 1. 73.5% of facilities horticulture farmhouse recognized that the prospect of greenhouse is bright, but 92.5% of the farmhouse also recognised that they need technical consultation on protected horticulture farming. Therefore, technical educations would must be enhanced about foundation of greenhouse and cultivation technique. 2. The holding times of explanatory meetings, cause of understanding to farmhouse, were one or two times in greenhouse construction, and 62.5% of the farmhouse expressed the insufficiency at the explanation and educational data. For this reason, it was judged that the construction contract had been delayed more than 5 months in 49.3% of the farmhouse after the decision of project budget. 3. In constructing after a contract, the rates of construction delay is 53.4% and defect occurrence is 41.1%. The biggest reasons of construction delay was insufficiency of worker and materials supply. Each percentage is 29.1%. And the reason of defect occurrence is badness of machinery equipment(62.9% ). 4. In management of greenhouse, a pipe-constructed plastic film greenhouse changes plastic film every one and three years because of sticking dust on plastic film. It was needed to about in cleaning technique of coverings. Because that used 3-5 years only half of the expected life span. 5. The order of broken rating in the subsidiary equipment is like this lollop ventilator (42.8%), a general control system(33.3%) especially, in the case of a general control system, the rate of all family can control is 52.7%. so, it is time to develop easy control equipment which every one could use as soon as possible. 6. When choose heat generator as decide capacity, the most priority is the mount of heat generator the percent is 45.5% heat generator and as decide model, the private purchase's percent is 77.3%. It is higher than a public bidding heat generator the percent is 22.7% heat generator when it compare with a public bidding. In the case of $CO_2$ generator, using rate is only 19.0%. The using rate is very low, so it needs education how to use depends on the way of the subsidiary equipment. 7. In the case of seedlings, it is asked to use factory-processed seedling effectively. because it's difficult to get security of labors(58.8%), hoped crops (55.9%) access same crops(29.4%) much more and changing of crops depends on market situation. that is the main reason the lack of knowhow.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.854-867
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• 2014

In the circumstance that high oil price state is continued over the world, the investment in crude oil development by oil major is a trend of increasing. Recently the number of delivered drill-ship for 5 years has been sharply increased all over the world and about twice than that of past 30 years. As addition to the increase of the drill-ship demand, the operation of drill-ships which is delivered recently is about 3,000 meters, ultra deep sea, on average and the work area is expending. Accordingly the drilling system including the size and length of pipe for drilling has been bigger and bigger and the power supply equipment for operation system also has large capacity. Unlike merchant vessel, high power and high voltage of diesel generators are required for drill-ship for which the demand for V-type 320 bore of diesel generator has increased. It is on the raised that the importance of lubrication oil cleaning for diesel generator on drill-ship which has longer time for construction, and also long term low load operation is unavoidable during commissioning of equipments. Recently it was reported that engine crankpin was damaged due to the hard contact caused by the abnormal wear down(Cam wear) on crankpin and bearing. The same pattern of wear down was found through the inspection on series vessels and the other vessel under commissioning. The purpose of this paper is to analyze of the wear mechanism based on the observation and theories and objective research from actual cases and to prepare the counter measures to avoid foreseeable damage when the lubricating oil is not properly cleaned.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.1971-1978
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• 2009

This study investigated the adsorption of safflower yellow dye on wool protein fiber and the optimum dyeing conditions to test color reproducibility. In addition, the effects of mordants on dye adsorption, color, fastness, and photofading rate were also studied. The prepared dye in powder form was characterized with UV-vis spectroscopy and FT-IR spectrometric analysis. The color of dyed fabrics was characterized by CIE $L^*a^*b^*$ coordinates, H V/C, and K/S values. The color reproducibility of the dyed wool fabrics was examined. The amount of dye adsorption increased and also, the shade of the dyed wool fabrics became deeper and more saturated with increasing temperature, time, and dye concentration. The maximum color strength was obtained at pH 3.0. The shade of dyed wool fabrics ranged from light yellow to dark mustard yellow as the pH of the dye bath shifted from alkaline to acidic. Color reproducibility was reliable with color differences in the range of 0.53~1.75. Fastness to dry cleaning was relatively good at 4/5 rating irrespective of mordanting. Fe and Cu mordants showed the least color change of the dyed wool fabrics after exposure to light. Mordants did not contribute to improve dye uptake and color fastness, although they made variations in color tone. Safflower yellow dye can be used satisfactorily without mordants and will not cause damage to the environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.603-608
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• 2018

Although the voltage-applied discharge method is most widely used in the semiconductor and display industries, periodic management costs are incurred because the method causes defects due to the absorption of ambient fine dust and causes emitter tip contamination due to the discharge. The emitter tip contamination problem is caused by the accumulation of fine particles in ambient air due to the corona discharge of the ionizer. Fuzzy ball generation accelerates the wear of the emitter tip and deteriorates the performance of the ionizer. Although a mechanical cleaning method using a manual brush or an automatic brush is effective for contaminant removal, it requires management of additional mechanical parts by the user. In some cases, contaminants accumulated in the emitter may be transferred to the wafer or product. In order to solve this problem, we developed an ionizer for a clean environment that can remove the pencil-type emitter tip and directly ionize the surrounding gas molecules using the tungsten wire located inside the ion tank. As a result of testing and certification by the Korea Institute of Machinery and Materials, the average concentration was $0.7572particles/ft^3$, the decay time was less than two seconds, and the ion valance was 7.6 V, which is satisfactory.