• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.560-568
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• 2007

This study was performed to compare the shear bond strength of primary enamel & dentin treated by AQ Bond $Plus^{TM}$ and G $Bond^{TM}$, recently developed 6th generation dentin bonding system, to that of Single $Bond^{TM}$ being widely used. Also by observing the resin tag under scanning electron microscope, Resin tags of each material were also observed under scanning electron microscope and compared to one another. The possibility of clinical application of All-in-One system which has an advantage to reduce chair-time for children with difficult behavior pattern was evaluated. The results obtained are as follows: 1. No statistically significant difference between groups was found in shear bond strength of primary enamel. 2. In primary dentin, the shear bond strength of AQ Bond $Plus^{TM}$ was $1.15\;{\pm}\;0.37\;MPa$, G $Bond^{TM}$ was $1.69\;{\pm}\;0.74\;MPa$ and Single $Bond^{TM}$ was $0.56\;{\pm}\;0.11\;MPa$. There were no statistical difference between AQ Bond $Plus^{TM}$ and G $Bond^{TM}$ and between G $Bond^{TM}$ and Single $Bond^{TM}$, whereas statistically significant difference was found between AQ Bond $Plus^{TM}$ and Single $Bond^{TM}$. 3. Under scanning electron microscope, resin tags observed in AQ Bond $Plus^{TM}$ and G $Bond^{TM}$ were very weak and tangled while strong and thick tags were shown with many lateral branches in Single $Bond^{TM}$. The result of the present study coupled with the advantages of less working time over the previous generation suggests that All-in-One system might be effectively used in adhesive dental procedures for primary teeth.

• Journal of the Korea Convergence Society
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• v.8 no.10
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• pp.333-338
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• 2017

Ethnography is concerned about specifically-based behavior and belief and the learned pattern of language and aims to describe and interpret them. Therefore, it is a classical form of qualitative research that was developed by anthropologists who spent for long time in conducting fieldworks within the cultural group. The results of analyzing ethnographic research methods of doctoral dissertations in Korea are as follows. First, the number of research participants in data collection methods was 1-10(32 dissertations, 44.4%), 11-20(18, 25%), 21-30(13, 18.1%), 31-40(2, 2.7%), and others(7, 9.8%). Second, data collection methods were in-depth interview(71, 98.6%), participant observation(70, 97.2%), document data(38, 52.7%), engineering device(12, 16.6%), and others(8, 11.1%). Data collection periods were 3-5 months(7 dissertation, 9.8%), 6-8 months(15, 20.8%), 9-11 months(14, 19.6%), 12-14 months(13, 18.1%), more than 15 months(17, 23.6%), and unpresented(4, 5.4%). Third, trustworthiness criteria were triangulation(46 dissertation, 63.9%), research participants' evaluation of study results 44(61.1%), peer researchers' advice and indication(33, 45.8%), follow-up(25, 34.7%), use of reference(20, 27.8%), reflexive subjectivity(17, 23.6%), intensive observation for a sufficient period(10, 13.9%), in-depth description(7, 9.8%), and others(7, 9.8%).

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.980-987
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• 2012

Nonpoint source pollution causes leaks and overtopping, depending on the state of the sewer network as well as aggravates the pollution load of the aqueous water system as it is introduced into the sewer by wash-off. According, the need for efficient sewer monitoring system which can manage the sewage flowrate, water quality, inflow/infiltration and overflow has increased for sewer maintenance and the prevention of environmental pollution. However, the sewer monitoring is not easy since the sewer network is built in underground with the complex nature of its structure and connections. Sewer decontamination mechanism as well as pipe network monitoring and fault diagnosis of water network system on system analysis proposed in this study. First, the pollution removal pattern and behavior of contaminants in the sewer pipe network is analyzed by using sewer process simulation program, stormwater & wastewater management model for expert (XP-SWMM). Second, the sewer network fault diagnosis was performed using the multivariate statistical monitoring to monitor water quality in the sewer and detect the sewer leakage and burst. Sewer decontamination mechanism analysis with static and dynamic state system results showed that loads of total nitrogen (TN) and total phosphorous (TP) during rainfall are greatly increased than non-rainfall, which will aggravate the pollution load of the water system. Accordingly, the sewer outflow in pipe network is analyzed due to the increased flow and inflow of pollutant concentration caused by rainfall. The proposed sewer network monitoring and fault diagnosis technique can be used effectively for the nonpoint source pollution management of the urban watershed as well as continuous monitoring system.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.17 no.1
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• pp.19-26
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• 2006

Objectives : The object of this study was to examine computer game playing patterns and psychopathologies related to computer game addiction in school-age children. Methods : The subjects were 533 elementary school students (4th to 6th grade) in Kangdonggu, Seoul. We evaluated computer playing patterns of all subjects using computer game playing pattern questionnaire, and determined the risk group of computer game addiction by internet game addiction scale score. We evaluated subscale score of K-CBCL from parents of all subjects, and conducted correlation analysis and logistic regression analysis between computer game addiction and subscale score of K-CBCL. Results : In 488 responders, 10.2% of started playing computer game in preschool age, and 67.2% started at low grade of elementary school. The mean frequency of computer game play per week was 3.66 days. Mean time spent playing computer games per day was 1.89 hours. 'Simply for fun' was the most common reason far playing computer games (40.8%). Male subjects showed statistically significant differences in age of starting computer game, frequency of computer game play per week, reasons for playing computer game and computer game addiction scale scores. There were significant correlations between computer game addiction scale scores and academic performance, somatic complaints, attention problems, and internalizing problems in K-CBCL. But In logistic regression analysis, only attention problems among K-CBCL subscales showed significant predictability to computer game addiction. Conclusion : Upper grade elementary school students experienced computer game playing at the very early age, and spend much time in playing computer games. There were significant correlation and predictability between computer game addiction and attention problems.

• Journal of Preventive Medicine and Public Health
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• v.18 no.1
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• pp.25-39
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• 1985

This study was conducted to assess the morbidity and medical facilities utilization patterns of the residents in urban low income area. Study population included 2,002 family members of 468 households in the low income area (LA) of Nam-san 4 Dong, Jung Gu of Taegu city and 1,709 family members of 374 households in surrounding neighbourhood control area (CA). Well trained nursing school students interviewed mainly with housewives according to the pretested questionaire between July 1 and July 30, 1984. Age-sex distribution of the study population in LA was similar to that in CA. The average monthly income of a household in LA was 236,000 won and 356,000 won in CA. Educational level of the residents in LA was lower than that in CA; average years of school education of the 20 years old or above in LA was 6.9 years compared with 8.5 years in CA. The average family members per room in LA was 2.6 and 2.2 in CA, and proportion of Medicaid program beneficiary was 29.4% in LA and 1.9% in CA. Prevalence rate of illness during 15-day period was 131 per 1,000 population in LA and 71 in CA(p<0.01) and that of the chronic illness for 1 year was 134 per 1,000 population in LA and 89 in CA(p<0.01). The most common illness experienced during 15 days was respiratory disease(24.0% in LA ana 29.8% in CA) and followed by gastro-intestinal disorders(21.0% in LA, 20.6% in CA). Injury or poisoning was 10.3% in LA and 3.3% in CA. Castro-intestinal disorder was the most common chronic illness in both LA (22.7%) and CA (21.7%), and followed by musculoskeletal disease in LA and neuralgia in CA. Mean activity restricted days among the persons with illness during 15-day period was 4.0 days in LA and 2.2 days in CA. Among persons with illness during 15 days, 17.9% in LA and 11.6% in CA did not seek any medical treatment and the most frequently utilized medical facility was pharmacy in LA (35.5%) and local clinic or hospital OPD in CA (42.1%). Among persons with chronic illness, 15.2% in LA and 9.2% in CA did not seek for medical treatment, and residents in LA as well as residents in CA utilized local clinic or hospital OPD more frequently than pharmacy or drugstores, especially those who have medical insurance. The most common reason for not treating illness experienced during 15-day period and chronic illness was economical constraint in both LA and CA. The higher prevalence rate of illness during 15-day period and chronic illness in LA than that in CA seems to be highly correlated with their lower economic status and educational level and crowded living condition. The utilization pattern of medical facilities was associated with the medical security status. A program to improve the economic status and living condition should be integrated with the health program to promote the health of the population in low income area.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.1-10
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• 2010

This study is about what process and methodology could make UI designer be able to achieve the interface which considers user's mental model through implementing corporate line-up model, when people design an interface between product of multi-function printer and user. The most important concern of UI designers who are dealing with an interface between product and user is how they can make product system image match user's mental model so that users can utilize products without any confusion and discomfort. If concept model which designers bring up and mental model which users expect and recognize could be of one accord, then users can feel ease of use toward products. The understanding and observation for user behavior and use pattern is prerequisite to develop user-centered interface between product and user. However, UI designers do design interface from their own perspective and assumption in many business areas, and users do not react as designers assumed and intended in many cases or examples. This study is to find inappropriate system images against users' mental model on basic function of multi-function printer, and the relationship of system image and user's mental model is diagramed to build up a hypothesis. The hypothesis from this study is validated through evaluation of domestic and international users. In addition, two suggestions to improve usability problems revealed from user test are proposed. The optimal solution is designed based on the result of user evaluation and consideration of many user environments, and then it is implemented to line-up product. In conclusion, this study considers how UI designers can create system image which is close to user's mental model.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.747-754
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• 2005

Nutritional regulation of gene expression associated with growth and feeding behavior in avian species can become an important technique to improve poultry production according to the supply of nutrients in the diet. Insulin-like growth factor-I (IGF-I) found in chickens has been characterized to be a 70 amino acid polypeptide and plays an important role in growth and metabolism. Although it is been well known that IGF-I is highly associated with embryonic development and post-hatching growth, changes in the distribution of IGF-I gene expression throughout early- to late-embryogenesis have not been studied so far. We revealed that the developmental pattern of IGF-I gene expression during embryogenesis differed among various tissues. No bands of IGF-I mRNA were detected in embryonic liver at 7 days of incubation, and thereafter the amount of hepatic IGF-I mRNA was increased from 14 to 20 days of incubation. In eyes, a peak in IGF-I mRNA levels occurred at mid-embryogenesis, but by contrast, IGF-I mRNA was barely detectable in the heart throughout all incubation periods. In the muscle, no significant difference in IGF-I gene expression was observed during different stages of embryogenesis. After hatching, hepatic IGF-I gene expression as well as plasma IGF-I concentration increases rapidly with age, reaches a peak before sexual maturity, and then declines. The IGF-I gene expression is very sensitive to changes in nutritional conditions. Food-restriction and fasting decreased hepatic IGF-I gene expression and refeeding restored IGF-I gene expression to the level of fed chickens. Dietary protein is also a very strong factor in changing hepatic IGF-I gene expression. Refeeding with dietary protein alone successfully restored hepatic IGF-I gene expression of fasted chickens to the level of fed controls. In most circumstances, IGF-I makes a complex with specific high-affinity IGF-binding proteins (IGFBPs). So far, four different IGFBPs have been identified in avian species and the major IGFBP in chicken plasma has been reported to be IGFBP-2. We studied the relationship between nutritional status and IGFBP-2 gene expression in various tissues of young chickens. In the liver of fed chickens, almost no IGFBP-2 mRNA was detected. However, fasting markedly increased hepatic IGFBP-2 gene expression, and the level was reduced after refeeding. In the gizzard of well-fed young chickens, IGFBP-2 gene expression was detected and fasting significantly elevated gizzard IGFBP-2 mRNA levels to about double that of fed controls. After refeeding, gizzard IGFBP-2 gene expression decreased similar to hepatic IGFBP-2 gene expression. In the brain, IGFBP-2 mRNA was observed in fed chickens and had significantly decreased by fasting. In the kidney, IGFBP-2 gene expression was observed but not influenced by fasting and refeeding. Recently, we have demonstrated in vivo that gizzard and hepatic IGFBP-2 gene expression in fasted chickens was rapidly reduced by intravenous administration of insulin, as indicated that in young chickens the reduction in gizzard and hepatic IGFBP-2 gene expression in vivo stimulated by malnutrition may be, in part, regulated by means of the increase in plasma insulin concentration via an insulin-response element. The influence of dietary protein source (isolated soybean protein vs. casein) and the supplementation of essential amino acids on gizzard IGFBP-2 gene expression was examined. In both soybean protein and casein diet groups, the deficiency of essential amino acids stimulated chickens to increase gizzard IGFBP-2 gene expression. Although amino acid supplementation of a soybean protein diet significantly decreased gizzard IGFBP-2 mRNA levels, a similar reduction was not observed in chickens fed a casein diet supplemented with amino acids. This overview of nutritional regulation of IGF-I and IGFBP-2 gene expression in young chickens would serve for the establishment of the supply of nutrients to diets to improve poultry production.

• Journal of the Korean Vacuum Society
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• v.16 no.5
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• pp.322-329
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• 2007

The interaction of oxygen with the ordered $Ni_3Al(111)$ alloy surface at 800 K and 1000 K has been investigated using LEED, STM, HREELS, UPS, and PAX. The clean $Ni_3Al(111)$ surface exhibits a "$2{\times}2$" LEED pattern corresponding to the ordered bulk-like terminated surface structure. For an adsorption of oxygen at 800 K, LEED shows an unrelated oxygen induced superstructure with a lattice spacing of $2.93\;{\AA}$ in addition to the ($1{\times}1$) substrate spots. The combined HREELS and the UPS data point to an oxygen chemisorption on threefold aluminum sites while PAX confirms an islands growth of the overlayer. Since such sites are not available on the $Ni_3Al(111)$ surface, we conclude the buildup of an oxygen covered aluminum overlayer. During oxygen exposure at 1000 K, however, we observe the growth of ${\gamma}'-Al_2O_3$ structure on the reordered $Ni_3Al(111)$ substrate surface. This structure has been identified by means of HREELS and STM. The HREELS data will show that at 800 K the oxidation shows a very characteristic behavior that cannot be described by the formation of an $Al_2O_3$ overlayer. Moreover, the STM image shows a "Strawberry" structure due to the oxide islands formation at 1000 K. Conclusively, from the oxygen interaction with $Ni_3Al(111)$ alloy surface at 800 K and 1000 K an islands growth of the aluminum oxide overlayer has been found.

• Journal of the Korean Society for Library and Information Science
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• v.10
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• pp.39-70
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• 1983

The concept of the public library defined by the Korean Library Association does not describe the current state of the Korean public library but describes the public libraries in the western society. Korean public library was formed after the western public library but it was modified and reconciled with the tradition of Korea. The difference between the concepts occured in the acculturation process of the Korean public library. According to the International Encyclopeadia of the Social Sciences, acculturation comprehends those phenomena which result when groups of individuals having different cultures come into continuous firsthand contact, with subsequent changes in the original cultural patterns of either of both groups. Korea opened its door to western world in 1876, and it began to contact with the western world. As the consequence, the concept of the public library of the West diffused to Lee Dynasty which were characterized by the confucianism and the extended family system. These two characteristics were against the public library concept and it could not function as it was and it had to be modified to fit to Korean society. The American public library was formed by the diffusion of English public library. The concept fitted in the colonial American society which was characterized by the Christianity and nuclear family system. Religion and family life were closely knitted together and they contributed much to the formation of the American public library. Also the society needed various information to form their new nation. The need of the public library grew and the public library repidly developed as the American society was urbanized and industrialized. The changes of Korean public library has passed the following process of acculturation. 1. The Korean culture contacted with Western world. 2. The public library concept diffused to Korea, but the people were illiterate and the need of the public library was for the preservation of the old books. The collection was not for people. 3. The function of the public library in Korea was altered slightly as several intellectuals who formed the first modern public library tried to literate Koreans as a means of liberation :from Japan through the library service. 4. The traditional libraries such as sodandg and hyangyo disorganized and finally disappeared as the traditional elements of the culture disappeared and the new cultural elements prevailed in Korea. 5. When the traditional elements of culture were disorganized, a reinterpretation of the diffused culture appeared. With the appearance of the vouth group which was not existed in the traditional society, cultural facilities for them were needed. They began to use public library as their reading rooms. This pattern has been institutionalized ever since in Korean public library. 6. When the new element of the culture spread, the traditional cultural elements react against this element. As the new public libraries sprung out, there were movements to restore the old Korean tradition of the family libraries and Hyangyo to counteract to the new libraries. This movements were not successful and they all disappeared as they could not keep up the rapid social change occurred in the Korean society. 7. In the process of the cultral change, cultural lag occurred between the public library and the users who could not adopt to the new library. This has been continued to the present time. 8. This diffused concept of the public library was modified and became native to Korean society. However, the acculturation of the public library concept has not changed the traditional ideas of Korean people and their behavior. The Korean society recently has been changing rapidly and the function of the Korean public library is improving accordingly; 1. The extended Korean family system is disorganizing. As the consequence, the public library could substitute the family system offering information and recreation service, etc. 2. The growth of educated population is requiring a variety of library materials. An individual library can not meet the needs of them and cooperative library service will be needed to share resources. The public library will become the center of the cooperative service. 3. The Koreans are watching TV more hours than they read printed materials. For them, the public library needs to collect audiovisual materials. Especially the teaching materials should be all audiovisualized for the effective teaching. 4. Technology is developing rapidly in Korea, especially computer technology is applied in many parts of the society. This will also influence library service. The public library will be developing as the centralized library computer system. When the Korean public library functions as the extended family system and the center of the cooperative library system, the Korean public library will be functioning as the public library defined by the Korean Library Association.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.265-272
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• 1999

In this study in order to know the behavior of mineral nutrients from forage plant to soil in a grassland ecosystem, the leaching of minerals (K, Mg, Ca, N and P) from air-dried (dead) plant body was investigated by putting orchardgrass (Dactylis glomerata L.) hay on meadow during a month with seasonal changes. The results obtained were as follows; 1) The K content of the forage, not stable during the experimental seasons, tended to decrease in the summer of 1986, while the Mg and Ca contents increased in the summer. The reason might be a different response (solubility or leaching liability) of the monovalent mineral (K) and divalent ones (Mg and Ca) in the forage to rainfall. 2) The percentage of P to the initial amount in the forage showed larger decrease in a rainy period (Feb.~Mar., 1986) and during the rainy summer (May to July). The P component of the forage might be easily leached with water. 3) The percentage of the four minerals (Ca, N, Mg, K) remained the least in the period of (Jun.~Jul., 1986), 4) Though the percentage of remained Mg and N of the forage varied very similarly, the percentage of remained N was higher than that of Mg during periods before summer (January to May), while after the period the ratio of the Mg seemed to be higher than that of the N (June to December), 5) During the periods until (May~Jun., 1986) the percentage of remained K and P of the forage varied in very similar pattern, and the order of remained mineral was as follows; $Ca>N{\geq}Mg>P=K$. But from the period of (Jun-Jul) the ratio of P remained in the forage increased nearly up to the ratio of N, and the order was as follows; $Ca>Mg{\geq}N{\geq}P>K$.