• Journal of Periodontal and Implant Science
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• 제29권1호
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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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• 제38권3호
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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.

• 마케팅과학연구
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• 제9권
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• pp.153-173
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• 2002

본 연구는 의복 구매시 소비자들에게 영향을 주는 의류점포의 서비스 품질, 의복평가 기준과 위험지각의 관계를 살펴보고, 이러한 관련변수들이 의복충동구매행동에 미치는 영향을 살펴봄으로써 의류제품을 다루는 마케터나 리테일러들에게 소비자 행동을 파악하는데 도움을 주어 차별적 경쟁우위 수단으로 활용할 수 있도록 하고자 하는데 그 목적이 있다. 연구 결과, 의복을 구매할 때 소비자가 지각하는 의류점포의 서비스 품질과 의복평가 기준은 구매와 관련된 위험지각과 부분적으로 관련이 있었다. 또한 의복충동구매행동에 대한 의류점포 서비스 품질, 의복평가기준 및 위험지각의 영향을 살펴본 결과, 위험지각요인 중 소비자들이 의류제품의 봉제상태가 나빠지지 않을까, 세탁/관리하기에는 불편함이 없을까 등의 관리적 위험과 다른 옷과의 조화나 비슷한 제품을 더 싼값에 살 수 있지 않을까 등의 성과적 위험, 그리고 점포분위기나 실내장식 등의 시설서비스가 의복충동구매행동에 영향을 미침을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제29권2호
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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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.

• 한국환경과학회지
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• 제23권5호
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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.

• 생물환경조절학회지
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• 제5권2호
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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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• 제38권7호
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• pp.854-867
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• 2014

지속적인 유가의 상승에 따라 국제 석유 자본들의 유전개발에 대한 투자가 활발하고 지속적으로 증가하고 있는 추세에 있다. 최근 5년 동안(2008~2013)에 인도된 드릴쉽(drill-ship)은 67척으로 그 이전 30년 동안에 인도된 척수의 두 배에 이른다. 그리고 최근에는 3,000 m 내외의 심해유전 개발이 증가하고 있다. 이에 따라 시추 장비와 시스템이 대형화 추세에 있으며, 이들의 운전을 위한 디젤발전기의 용량이 증가하였다. 디젤발전기 용량은 일반 상선과는 달리 고출력 및 고전압이 요구되며, 이를 충족시키기 위하여 V-type 320 mm 실린더 내경의 고출력 엔진에 대한 수요가 증가하게 되었다. 드릴쉽의 경우 일반 상선 대비 선박건조 기간이 길어짐에 따라 커미셔닝 기간 중 장시간 저 부하 운전이 불가피하여 엔진 윤활유 관리의 중요성이 대두되었다. 최근에는 선박인도 전 크랭크핀에 캠마모(Cam wear)와 같은 이상마모가 발생하였으며 시리즈 호선 및 관련 호선들에 대한 크랭크핀의 전수 검사 결과 정도의 차이가 있었으나 모두 크랭크핀에 이상마모가 발생한 것이 확인되었다. 본 논문은 실제 호선에 적용된 엔진 크랭크핀의 이상마모 발생 원인에 대해 이상마모 메커니즘 분석과 실증결과 분석을 통하여 재발방지를 위한 대책 방안에 대하여 논하였다.

• 한국의류학회지
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• 제33권12호
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• pp.1971-1978
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• 2009

본 연구는 염색 공정의 표준화와 재현성을 확립하기 위해 홍화 황색소의 모섬유에 대한 염색성을 조사하는데 목적이 있다. 홍화 황색소는 물로 추출한 후 농축, 동결건조하여 분말상태로 만들어 사용하였다. 염색 온도 및 시간, 염료 농도, 염액의 pH 등에 따른 염착성과 색상 변화에 대해 조사하였으며, 세탁 및 일광견뢰도를 평가하였다. 염착량은 $50^{\circ}C$까지 서서히 증가하다가 이후 급격히 증가하여 $90^{\circ}C$에서 최고 값을 나타냈다. 염착은 초기 10분 이내에 빠르게 일어났으며 이후 서서히 증가하다가 40~60분 사이에 평형에 도달하였다. 염료 농도가 증가함에 따라 염착량이 계속 증가하여 점점 진하고 어두운 노랑색이 되었다. 산성 조건에서 염착이 잘 되었으며 pH 3.0에서 최대염착량을 보였다. 얻은 결과를 근거로 최적 염색 조건은 $90^{\circ}C$, 40분, pH 3.5으로 설정하였으며, 최적 조건에서 염색한 시료들 간의 색차는 0.53~1.75로서 재현성이 우수하였다. 후매염은 염착성 증진에 효과가 없었으나, 다양한 톤과 농담의 노랑색을 얻을 수 있었다. 세탁(드라이크리닝)견뢰도는 4/5등급으로 좋은 편이었으나 20시간 조사 후 일광견뢰도는 Fe과 Cu매염한 경우 3/4등급으로 색차가 가장 적었다. 결과를 종합해 볼 때 매염제가 색상톤을 다양하게 하는 효과는 있었지만, 염착량과 견뢰도 향상에 기여하지 못하였다. 홍화 황색소는 모염색에서 매염제 없이 만족스러운 결과를 얻을 수 있고, 따라서 환경에 피해를 주지 않을 것으로 사료된다.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.603-608
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• 2018

전압 인가식 제전방식이 반도체나 디스플레이 산업에는 가장 많이 사용되고 있지만, 방전에 의한 주변 미세 먼지의 흡착 및 전극핀의 오염으로 불량 발생의 원인을 제공하므로, 주기적인 관리 비용이 발생하게 된다. 전극핀의 오염 문제는 코로나 방전으로 인하여, 주변 공기의 미세한 입자를 축적함으로 생성된다. Fuzz ball의 생성은 전극핀의 마모를 촉진 시키고, 또한 정전기 제거 장치의 성능을 저하시킨다. 오염물 제거 방법은 수동 브러쉬 및 자동 브러쉬를 이용하여 기계적인 세척 방법이 효과적이지만, 추가적인 기계부품이나 사용자의 관리를 요구한다. 일부의 경우에는 이미터에 축척된 오염물이 웨이퍼나 제품에 전이될 수도 있다. 이러한 문제를 해결하기 위해, 제전기의 외부로 돌출되는 전극핀을 없애고, 이온탱크 내부에 위치한 텡스텐 전극선을 이용하여 주위 기체 분자를 직접 이온화할 수 있는 청정 환경에 적합한 정전기 제거 장치를 개발하였다. 한국기계연구원에서 시험인증한 결과, 오염 입자는 평균 $0.7572particles/ft^3$이고, 제전 시간은 2초 이하 이며, 잔류 전위는 7.6V로 만족할 만한 결과를 얻었다.