• Journal of dental hygiene science
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• v.14 no.3
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• pp.405-410
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• 2014

The purpose of this study in vitro investigation was to compare the marginal and internal fit of Ni-Cr alloy metal ceramic crown before and after porcelain veneering. Furthermore, this study evaluated whether the influence of the porcelain firing on the precision of fit of dental prostheses. The maxillary right incisor was selected as an abutment for experiments. Ten working models were prepared. Ni-Cr alloy cores appropriate for each abutment were prepared by lost wax technique. The marginal area and four internal areas of the crowns were measured at two stages: before veneering process and after upper porcelain firing. Silicone replica techniques were used. The data were statistically analyzed with the paired t-test (${\alpha}=0.05$). $Mean{\pm}SD$ marginal and internal gap were $67.1{\pm}23.3{\mu}m$ for the nickle chrome alloy core group and $74.4{\pm}21.9{\mu}m$ for the metal ceramic crown group. There were statistically significant differences in all investigated areas (p<0.05). Within the limitations of this study, none of the Ni-Cr alloy metal crown values measured after porcelain firing process exceeded $120{\mu}m$, which is the clinically acceptable threshold.

• Journal of the Korean Dietetic Association
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• v.5 no.2
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• pp.153-163
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• 1999

The purpose of this study was to obtain basic data of nutrition education for obese children and to examine food habits, food behaviors, and nutrition knowledge. A convenience sample of 84(male:62, female:22) obese children was selected from "98 Children Nutrition Camp". The survey design employed a structured questionnaire. The results of this study were summarized as follows. 1. The percentage of the subjects who overestimated their body weight was higher in female compared to male. Only 35.9% of highly-obese subjects considered them as 'very fat'. The experience of weight control was higher in female than in male, and it was also higher moderately- or highly-obese subjects compared to mildly obese. 2. 64.3% of subjects reported that they regularly eat breakfast. The percentage of the subjects who indicated that they eat at regular meal time or they eat very irregularly was highest in the highly-obese subjects. 3. 34.5% of subjects reported that they eat very fast. The eating speed was slower in female compared to male, and in obese subjects. 55.4% of subjects reported that didn't eating out. 4. 80.9% of subjects had snacks, and most of them had snack between lunch and dinner. The reason the subjects eat snack was hunger. The most favorite snack was cookies. 5. The most preferred and distasteful food was meats(32.1%) and vegetables(67.1%), respectively. 6. The score of food behaviors was relatively low in most subjects. 7. The level of nutrition knowledge was in order of fair(83.1%), poor(9.6%), excellent(7.3%), and was higher in male compared to female. Consequently the results of this study showed to disagreement among food habits, food behaviors and nutrition knowledge, and feel keenly the necessity of education connecting of these. This education had to be practical education to change food behaviors.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.110-126
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• 1995

Korean economy has been developed successfully in the course of implementing the five year economic development plans since 1962. The gap of incomes and quality of life between rural and urban area has been widened and it made rural farm laborers drain to urban areas. Therefore the prevailing situation of labor shortage and wage hike in rural area has made farm management deteriorate in recent years. Under the internal and international unfavorable economic conditions, marginal farm land of 66.5 thousand ha has been idled as of end of 1993. The total area outside agricultural development zone with bad farming conditions including irrigation and drainage, and land consolidation for mechanization were estimated at 360.4thousand ha equivalent to 17.5% of the total farm land area in Korea. Considering the topographical conditions of marginal lands, the effective use of marginal lands should be studied from the view point of public interest rather than from the view point of individual economic conditions. Considering the present agricultural economic settings, such as price decrease, unfavourable benefits of farm products, labour shrotage, free trade of farm products and poor physical condition of marginal lands, the institutional and realistical measures for the effective utilization of idle and marginal land should be studied as soon as possible. Detail land use pattern should be surveyed in the areas outside agricultural development zone and have to be classified as orchard farms, grass land, fish culture farms, lawn and ornamental tree farm, sight seeing and leisure farms for urban peoples, special crops production farms and common farms to be developed for farm mechanization. According to the surveyed results, the expected utilization patterns of the idle and marginal lands could be considerd as village common use, farm land base development, leisure farm development, mutual complementary utilization between urban and rural areas, G't purchase and management, credit supply and new extension services, improvement of cropping patterns and sight seeing and leisure farm patterns. For the successful and reasonable management of the marginal lands, the actions such as institutional improvement, prohibition of idle marginal land, enforcement of activities of farm management committee members and land banking system of RDC including development and utilization systems should be included.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.153-161
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• 1998

Concrete structures has been deteriorated by and freezing the thawing due to temperature gap. This study was conducted to evaluate durability of concrete which are increasingly demanded recently. Therefore the research of durability must be executed for application of waste foundry sand concrete real structures. Concrete durability properties incorporating waste foundry sand was performed with the variable of W/C ratio. Sand/Waste foundry sand ratio and Air entrainment-Non air entrainment. Cylinder specimens were made and subjected to freezing and thawing cycle at -18$^{\circ}C$ and 4$^{\circ}C$. Dynamic modulus of elasticity were evaluated as F/T cycle increase. The results show that strength of concrete is increased the W/C ratio decrease, the Sand/Waste foundry sand ratio increases when the concrete contains AE agent and decreasing W/C ratio and AE concrete makes improved resistance of freezing and thawing improved. Especially, resistance of freezing and thawing is improved by Fine aggregate/Waste foundry sand ratio which is 50%, 25%, 0% in a row. Therefore it is turn out the waste foundry sand could be applied to concrete from the experiment.

• Journal of the Korean Society of Fashion and Beauty
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• v.3 no.2 s.2
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• pp.55-64
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• 2005

The purpose of this study is to investigate consumers' knowledge and preference towards functional cosmetics. Through the beauty advisors' surveys, their own selling styles and consumer behaviors recognized by beauty advisors were analyzed. It was intended to help extend and strengthen the functional cosmetic market which has continued to grow rapidly since the approved goods under cosmetic law in 2001. For this study, the data was collected through questionnaires the professional consumer counselors confirmed from Korean women over the age. of twenty old living in the Seoul and Kyoungki areas. After pre-research was implemented on 45 women, 328 samples were analyzed as final samples. In addition,46 samples, which were collected through the questionnaires from beauty advisors were analyzed. Samples were analyzed by frequency, percentage, T-test, ANOVA using the SPSS program. The results of study were as follows: First consumers recognized whether functional cosmetics or not. According to the beauty advisor's surveys, consumers regard the functional cosmetic boundary as being wider than real functional cosmetic boundary according to cosmetic law. So, there is a gap between consumers' opinions and real law. Second, regarding the purchasing channels, the largest channel is the cosmetic store. As far as consumers are concerned the most important factor when buying cosmetics, is the suitability of their own skin types. The second factor is product quality and the third factor is price. Functional cosmetics non-experienced group are more concerned with price compared to experienced group. Related to purchasing products, functional cosmetics experienced group buy set products compared to non-experienced group buy one product. Third, the ultraviolet filter cosmetics portion is the largest in the functional cosmetics market the second largest portion is bleaching cosmetics and the third largest portion is the anti-senility cosmetics. However, Most preferred by consumers is the anti-senility cosmetics. Moreover, preference for ultraviolet filter cosmetics is the least. Finally, the level of satisfaction for functional cosmetics is high and dissatisfaction is low. Consumers feel that beauty advisors are simply pushing high priced products without recognizing the consumers' real needs. In conclusion, to develop the functional cosmetic market continually in the future, it needs to extend various products and advertise them until consumers are more aware.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.3
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• pp.67-73
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• 2009

Compared to the chip-bonding process utilizing solder bumps, flip chip process using Cu pillar bumps can accomplish fine-pitch interconnection without compromising stand-off height. Cu pillar bump technology is one of the most promising chip-mounting process for RF packages where large gap between a chip and a substrate is required in order to suppress the parasitic capacitance. In this study, Cu pillar bumps and Sn bumps were electroplated on a chip and a substrate, respectively, and were flip-chip bonded together. Contact resistance and chip shear force of the Cu pillar bump joints were measured with variation of the electroplated Sn-bump height. With increasing the Sn-bump height from 5 ${\mu}m$ to 30 ${\mu}m$, the contact resistance was improved from 31.7 $m{\Omega}$ to 13.8 $m{\Omega}$ and the chip shear force increased from 3.8 N to 6.8 N. On the contrary, the aspect ratio of the Cu pillar bump joint decreased from 1.3 to 0.9. Based on the variation behaviors of the contact resistance, the chip shear force, and the aspect ratio, the optimum height of the electroplated Sn bump could be thought as 20 ${\mu}m$.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1140-1147
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• 2016

The plasma and serum of Crocodylus siamensis have previously been reported to exhibit potent antimicrobial, antioxidant, and anti-inflammatory activities. During wound healing, these biological properties play a crucial role for supporting the formation of new tissue around the injured skin in the recovery process. Thus, this study aimed to evaluate the wound healing properties of C. siamensis plasma and serum. The collected data demonstrate that crocodile plasma and serum were able to activate in vitro proliferation and migration of HaCaT, a human keratinocyte cell line, which represents an essential phase in the wound healing process. With respect to investigating cell migration, a scratch wound experiment was performed which revealed the ability of plasma and serum to decrease the gap of wounds in a dose-dependent manner. Consistent with the in vitro results, remarkably enhanced wound repair was also observed in a mouse excisional skin wound model after treatment with plasma or serum. The effects of C. siamensis plasma and serum on wound healing were further elucidated by treating wound infections by Staphylococcus aureus ATCC 25923 on mice skin coupled with a histological method. The results indicate that crocodile plasma and serum promote the prevention of wound infection and boost the re-epithelialization necessary for the formation of new skin. Therefore, this work represents the first study to demonstrate the efficiency of C. siamensis plasma and serum with respect to their wound healing properties and strongly supports the utilization of C. siamensis plasma and serum as therapeutic products for injured skin treatment.

• Journal of Korean society of Dental Hygiene
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• v.6 no.4
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• pp.325-337
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• 2006

The purpose of this study was to examine the oral health state of the elderly in an effort to pave the way for dental health project planning for the elderly for the city of Jeonju and to help promote the oral health of the elderly population to which health care services weren't accessible a lot. The subjects in this study were 300 elderly people who were in their 60s and up and used 10 different welfare establishments for the elderly in Jeonju. A survey was conducted from May 3 through 13, 2005, by interviewing them in person, and the collected data were analyzed. The findings of the study were as follows: 1. In terms of the period of oral health examination, 44.1 percent of the 66-70 age group, 48.1 percent of the elementary school graduates and 39.4 percent of the house owners had their teeth examined whenever they had a toothache. So their cycle of oral health examination was statistically significantly different according to age(p<.05), education(p<0.001) and form of residence(p<0.001). 2. Regarding the necessity of prosthesis, prosthesis was needed by 52.1 percent of the age group from 71 to 80, 44.3 percent of the women, 48.9 percent of the men, 60.0 percent of the community college graduates and 55.9 percent who rent a house on a deposit or monthly basis. But there was no statistically significant gap among the groups. 3. As for the necessity of oral health education, the necessity of it was absolutely supported by 89.7 percent of the 66-70 age group, 76.0 percent of the women, 87.2 percent of the men, 95.3 percent of the middle school graduates and 87.7 percent of the house owners. Their age(p<.0.01), gender(p<0.05) education(p<0.05) and form of residence(p<0.01) made a statistically significant difference to that. 4. Concerning oral health education experience, 79.3 percent of the high school graduates and 79.8 percent of the house owners had never received oral health education, and that experience statistically significantly varied with education(p<0.001) and form of residence (p<0.001). 5. As to the biggest reason for oral health care, 50.0 percent found it necessary to take care of their teeth to ensure their own perpetual oral health, and 33.7 percent felt the need for that because they had a toothache. The above-mentioned findings indicated that the elderly people were definitely in want of oral health education. Dental hygienists in public dental clinics should serve as dental health educators to address their needs, and regular oral health care programs should be prepared to spread awareness about the importance of oral health among elderly locals.

• Journal of Korean society of Dental Hygiene
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• v.6 no.4
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• pp.349-359
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• 2006

The purpose of this study was to help improve the quality of education to keep up with fast-changing environments in educating sector. Relevant literature and data were reviewed, and the subjects in this study were dental hygiene juniors at seven two-year colleges in the Seoul metropolitan area and other regions, on whom a survey was conducted for about three months from August through October, 2004, to assess their satisfaction level with their major and educational environments. And it's concluded that in order to attract more new students and foster qualified students, dental hygiene practice labs should be improved on a large scale, and that there should be a great deal of investment in teaching facilities. The major findings of the study were as follows: 1. As for satisfaction with major choice, 57.5% of the students investigated, the largest percentage, expressed satisfaction with their major. 27.8%, the second largest group, found their choice not to be bad. 2. Regarding satisfaction with the state of practice labs, 41.9% were pleased with practice labs. This rate was quite lower than that of nursing students, as 64.2% of nursing students were pleased with their practice labs.7) 3. As to satisfaction with individual practice labs, oral prophylaxis labs were considered most satisfactory, as 53.9% were satisfied with them. Digital radiation labs appeared to be satisfactory the least, which made 77.0% dissatisfied. 4. Whether there were any connections between their working experience as a clinical worker and satisfaction level was investigated. In terms of their satisfaction with major choice and the state of practice labs, the students who had ever worked as a clinical worker were relatively pleased with the state of practice labs. As for satisfaction with each practice lab, those who had ever served as a clinical worker before being admitted into college expressed more satisfaction with radiation practice labs(p<0.05) and digital radiation labs(p<.05) than the others who hadn't. The gap between the two was statistically significant. 5. In regard to the causes of dissatisfaction with practice labs, 93.7 and 80.0% were respectively dissatisfied with digital radiation labs and basic dental hygiene labs because their colleges were devoid of those labs. 51.6%, the largest group, found oral prophylaxis labs unsatisfactory because of their frequent breakdown. In the event of most of the other practice labs, the greatest percentage were discontented due to a shortage of equipment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.430-430
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• 2007

In general, polyimides (PIs) are used in liquid crystal displays (LCDs) as alignment layer of liquid crystals (LCs). Up to date, the rubbing alignment technique has been widely used to align liquid crystals on the PI surface, which is suitable for mass-production of LCDs because of its simple process and high productivity. However, this method has some disadvantages. Rubbed PI surfaces include the debris left by the cloth and the generation of electrostatic charges during rubbing process. Therefore, rubbing-free techniques for LC alignment are strongly required in LCD technology. In this experiment, PI was uniformly coated on indium-tin-oxide electrode substrates to form LC alignment layers using a spin-coating method and the PI layers were subsequently imidized at 433 K for 1 h. The thickness of the PI layer was set at 50 nm. The LC alignment layer surfaces were exposed to an $Ar^+$ ion-beam under various ion-beam energies. The antiparallel cells and twisted-nematic (TN) cells for the measurement of pretile angle and electro-optical characteristics were fabricated with the cell gap of 60 and $5\;{\mu}m$, respectively. The LC cells were filled with nematic LC (NLC, MJ001929, Merck) and were assembled. The NLC alignment capability on ion-beam-treated PI was observed using photomicroscope and the pretilt angle of the NLC was measured by the crystal-rotation method at room temperature. Voltage-transmittance (V-T) and response time characteristics of the ion-beam irradiated TN cell were measured by a LCD evaluation system.